SLP2000: Both Deus Ex and Thief are worth 10$.
You make mistake comparing Digital sales to retail sales.
With retail sales of old games, after some time prices are reduced because they just want to sell all produced copies to get at least production price. Publisher already earned theirs, and now they just have to utilise what's left. And if they sell it very cheap, they just withdraw the production costs.
In case of digital sales, it's not the case, so you'll never see prices going that much down - it's just not worth to sell Deus Ex for 5$. But, we got promo sales every weekend, and big sales every Christmas. You don't have it here (maybe in USA it'sdifferent).
This is true, your point is valid. Still, digital releases have a better price than physical copies most of the time when there are promos and nice deals. I bet you cant buy a physical copy of Deus Ex 3 for 10 dollars anywhere, yet Amazon had this price for the digital version on Christmas sale. The costs of getting a digital copy out is much lower than a physical one.
I dont know how many people here are like me, but i always prefer the physical copy over the digital one. Its just better to own the physical DVD with case, artwork and manual. Even though i prefer physical copies, i buy more digital games than physical for one reason: price. Digital copies just get too cheap on deals.
Now, when a physical copy is cheaper than the digital one, i wont even think twice. Its a no brainer. Just think about it, you can get the complete Thief series on a beautiful physical copy with case, artwork, manual, for 10 dollars, which is the price of the first Thief alone on GOG. For me, theres no reason to buy Thief on GOG other than to show my support.
Im not complaining or anything, i do know that this isnt GOGs fault, and Thief is definately worth 10 dollars, even more. But considering the circumstances, its overpriced.