Of course. If 100 people are absolutely going to buy a game and the regular price is $10 and the sale price is $2 and all 100 people buy the game, and they all pay $10, that would support GOG (or whoever) more than if everyone paid the sale price. That much as you suggest in less words goes without saying so to speak. ;o)

But that is a math textbook example where a guaranteed 100 people are buying something no matter what, and that's not really how the real world works for selling products. It's much more complicated than that. There are things people absolutely need such as food items, and things people don't really need like video games, and the pricing of these items will vary accordingly. But for a given item that is an optional purchase, people will more often follow a tendency to not buy things they don't really need and don't really have a strong burning desire to own immediately and thus no sale at all happens, and people have an increasingly higher likelihood of making a purchase of something they want but don't really really need the lower the price goes, and if the price goes low enough a lot more people are much more highly likely to buy things they don't need at all and in many cases may never even use.

In the case of digital video games, they take up no physical space, no warehouse and essentially any sale is 100% profit divided amongst the distributor, publisher, developers, electricity company, ISPs, and the tax man. A sale made at any price whatsoever is positive revenue that does not exist if the sale does not happen, so every sale is a good sale and once enough of the product has sold to cover the costs of making it, every cent made after that is 100% pure profit. If a game is priced at $20 such as Sim City 4 which is over a decade old, the price seems excessively high (to me) for such a game since it is so old and compared to what else you can get for $20 it just seems out to lunch. Put that game on sale for $5 and we're supposed to believe that the programmers are starving and desperate to make money that they are bending over and begging us to buy it? Nonsense! The $5 price charged is what the game is actually worth - at best right now, and they know this so the prices are dramatically over-inflated to begin with. They'll get a slow trickle of people buying it at $20 or some other game at $10 day to day from people who care more about getting something /right now/ and less about what it is actually worth, and so they can charge that price so that when they put the sale on for $5 it looks like this mind blowing OMG sale of the century that they're almost paying you to take it and all of the developers and their families are going to have to eat bread and water for the next 6 months and starve. The reality is the demand the sales create cause zillions of people to climb the walls to buy the game in droves, including shit tonnes of people who will probably never even install or play the game. Statistically something like 75% of all games bought on steam are never even installed or something like that. That's a lot of whimsical purchases people made which produced pure profit for the distributor, publisher, developer, janitor, tax man, etc. with practically zero ongoing maintenance costs. It's all pure profit, and they eat steak and lobster not bread and water. Sell 10000 copies of a game for $5 in a one week sale and you make $50000 with zero overhead costs. Sell 500 copies of the same game in one week at $20 a shot and you only make $10000. That's one fifth the cashflow. The deep discount sale makes massive profits. Plus since the whole industry knows this, they purposefully overinflate the regular game prices so that the sales look better than they often really are.

There is absolutely not even the slightest reason to feel guilty about buying a $20 game for $0.50, nor for purposefully waiting for it to go on sale for that price if you wish to. The people who make the game are getting their money along the way just fine unless the game sucks in which case maybe they should be looking for a new line of work anyway. :) Nobody should ever feel obligtated to pay a cent more for something than what the price it is being advertised for, and not a cent more than they personally are willing to part with for it. If I'm willing to pay no more than $2.99 for say... Omerta including all DLC, then that is what I value the game is worth to me. I have no obligation to ever buy it and the game developer/publisher and GOG has no entitlement owed to them from me to buy it ever. I choose what it is worth to me personally and individually, and they choose the profit they want to make from it. In this negotiation if our two numbers cross and I'm aware of it, a business transaction may take place... or it may not. The only way a transaction happens is when both parties agree mutually that the terms of the sale are mutually agreeable and fair and reasonable regardless of what the terms turn out to be. If either party truly disagrees then either the purchaser refuses to buy or the seller refuses to sell. Capitalism strong at work. No entitlements and no obligations.

In some cases however we may personally feel some kind of emotional reason that we may desire to pay more for something voluntarily because we feel it helps out someone or to show our support and if we feel the desire to do so, then go for it I say, but we should never feel any sense of obligation to do so. For example, I am very happy about GOG and CD Projekt and The Witcher 3 is almost certainly going to be the first game over $12 that I've bought since 2007 when I buy it. I will probably buy the pre-release just before it is released and I probably wont ever do that again until their next game comes out. In fact, I'm unlikely to spend more than $5 max on any single game anytime in the near future and more likely most of them will be under $3 or less as I have like 700 games and don't ever even need any more of them. But I have a burning fire in me to throw a suitcase of money at GOG for The WItcher 3 so to speak, so my normal thought processes about this stuff are completely non-existant concerning that one very special game. Rarely does a game give me goose pimples but that one sure does. :)

That is easy, as I said above, GOG has the rights to sell these games. Every game they sell is pure profit divided between them and the various other parties that take their slices of the pie with next to no overhead. A game sold at any price is almost all profit minus the small overhead of running the business and whatnot. A game purchase is a few numbers changing places in some computer's memory and hard disk, and money changing hands through the flow of electrons with next to zero human being involvement. The games are a flow of electrons over copper etc. that cost next to 0 to provide, so it is almost all profit whether it is sold for $2 or $20. The lower the price, the higher the volume of sales will be and vice versa. If you graph out product price versus number of units sold it generally produces a nice bell curve of some form with the peak of the curve being the maximum profit point. The prices games are sold at on sale are normally going to likely be at that peak spot on the bell curve which maximizes profit. We are under the illusion that we're getting an amazing deal when in reality we're purchasing these things at exactly the price that will produce either the maximum profit, or something that produces significant direct profit, or indirect profit by drawing attention (promotion). Either way, sales exist to promote products/services/businesses and draw customers and all of that ultimately produces more profit. So they make money because they are good capitalists playing the game the way it is supposed to be played - economics 101. :)