Nah, Perimeter (as well as a few other 1C games) just got a custom lower price at some point. Used to be 5.99 as well.

The only games that got price hikes from $5.99 are the Interplay catalog but that was Interplay's choice not GOG.

order #AM090002613


Fallout Classic 5.99

Fallout 2 Classic 5.99

Fallout Tactics Classic 5.99

Earthworm Jim 3D 5.99

Earthworm Jim 1+2: The Whole Can 'O Worms 5.99

Redneck Rampage Collection 5.99

Lionheart: Legacy of the Crusader 5.99

All of those have a base price of 9.99 USD (and NOT 13 or more as you said), and it may have to do with the fact that the early Fallout games were first completely removed from the store, and later returned by Bethesda instead of Interplay who had the rights to them previously.

Also 9.99 USD. See Interplay argument in multiple previous posts.

"Every game", huh?

Yes, how much more clear do you want me to be, don't even bother replying, your trolling's not gonna work on me

Debunk the size of my ass, you're not getting me to cross reference my entire fucking library

Confusion between CAD and USD.
Nah, it was also Interplay.
https://www.gog.com/forum/general_archive/special_promo_whole_interplay_catalog/post274

Not sure if the OP meant it this way, but prices have definitely been rising. Just look at the soldier of fortune release recently. What would once of been a 2-3£ release is now (I can't check exactly as site is broken on my mobile and I only see prices in francs!) substantially more than this. Add in the disappearance of all goodies, being palmed out to dlc or what not. And also the prevalence of the confuse and profit method of multiple versions, pre order only and such like, and costs are definately rising. I am not particularly against this, although we never saw the massive savings going from physical to digital, but there definately is a rise in prices, perhaps to support other functionality like galaxy.

No need to "cross-reference your entire library", OP. Just look at this:

EA catalog link

All the old stuff should be 7-8 CAD, I suppose, considering the USD-CAD conversion.

Bonus SqEnix catalog, more unchanged prices

Just like everybody told you, it's just the Interplay catalog that got increased to 10USD (13CAD at current rates).
It happened like 5 years ago.

Interplay's done it at least a couple different times, in batches. I'm pretty sure I remember it happening at least once in the last couple years; but definitely since I've been a GOGarino (and that's not counting their re-release of the old Descent games at higher price points after their legal issues with the games' other rights-holders were settled somehow).

But yeah, OP doesn't know the difference between "some" and "every single one, no exceptions!"

Now that you mention it, I seem to have been rather off on that one. Going by the prices in my orders history, I suppose most were hiked around 2 years back. Maybe I conflated it with the removal of the Fallout games.

Shoe me once, shoe's on me...

Sure. Let's go through this step-by-step:

1. The avatar implies someone of a weightier nature. Based off visual approximation through computer imaging techniques, this would suggest that the size of your keister is around 42 inches, give or take.
2. However, your avatar also seems to be a female. By general law of the internet, 80% of all users who use a female avatar are actually males, making it statistically likely that you are indeed a male.
3. If we assume you're a male and that your avatar is lying, it follows that the rest of the avatar is lying, meaning that you look nowhere near what it presents (and quite frankly, I hope to God that you don't).
4. Since males, on average, exaggerate their features by about 6% (again using statistics), we can deduce that your rear end is actually around 6% smaller than you claim it is. As such, we have an estimate of your butt being about 40 inches wide.
5. We can't stop here, however, since we have to take physiology into account as well. The amount of butthurt you have for people who try to help you answer your questions indicates a reduction in the rear end of about 5-6 inches, putting you somewhere in the range of approximately 35 inches.
6. This in itself is reduced further as high sodium intake can sap muscle size by absorbing water, so we have to take off another 2-3 inches due to the amount of salt you have against somebody trying to point out the difference between the terms "some" and "literally every" and suggesting you list some games for an example such that others can better help you. This places you at about 32 inches.
7. In conclusion, your butt is nearly 10 inches scrawnier than you'd have us believe.

Any questions?

None of your example have base price at $13 or $12.99, or similar price.