EastTNGamer: I believe that the law should be the same as it is with all other IP property, such as books, audio CDs, etc.
Any reselling would have to occur via an approved reseller, who would also get a cut, just to ensure that the digital product wasn't sold by the same person more than once.
If that didn't occur, then you would just be giving a license to some folk to continually make money, on something they no longer have a legal right to. Thus it would be a tricky and complex endeavor to keep tabs of. So while I agree in principle, as I am sure do many others, it is fraught with difficulties.
Just follow the logic of all that would be required. And of course, I am ignoring the fact, that the original owner might do the wrong thing and keep a copy for themselves. For starters, if it was a GOG game, GOG would have to be the reseller, so that there was a record and it can be removed from the original account and transferred to another. GOG would of course need to get a cut, for their time and effort etc.
And while GOG might be prepared to trust, because naturally they are getting some value from their cut, the DEV and PUB of the game, would be needing to trust too, and that is likely where any difficulties would lie.
And unlike a physical product, where you get degradation over time, no such thing occurs when digital.
So keep following the logic.
If me and 9 mates, created some kind of purchase group, where one copy of each game is bought, and then sold on to each member in turn, for a very low sum, that could equate to 10 gamers getting the game for next to nothing. The only overhead, would be the cut to the reseller. So GOG would need to dictate the reselling cost, and of course the DEV and PUB would want a significant cut of that too, or they would be losing out on sales.
And following the logic further still.
Once it became known you were allowed to resell a digital product, then you would be relying on folk knowing all the ins and outs of the legal aspects, and continually remembering such. For example, who they are allowed to buy a resale product from. You couldn't just trust anyone who wanted to sell such a product to you. There would need to be some way to get proofs or you would have wrong doers essentially printing money ... and so think about the full ramifications of that, beyond the digital product in question.
And there is much more of course.
Really the only acceptable approach, would be at an approved cost and via an acceptable reseller. That approved cost might not be the current price, especially if that is high, but equally it would not likely be at a deep discount price either. So if the original owner got it for a deep discount, then potentially they would be making a profit on a resale.
The more you dig, the more complex it all becomes. And that is no doubt why current lawmakers are struggling with the issue.