Word. Metro 2033, the base game, was probably one of the most discounted games ever. It was given away for free on PC in multiple occasions. Outside of that, it was in 1$ bundles and similarly low prices have been thrown around on Steam as well. On console, the game costed 5 bucks or so more than once. The sequel didn't get this kind of treatment, but its price went down pretty damn fast. I don't see why this remake shouldn't be costing like half price in a few months.
The reason Metro 2033 was so cheap and so often is that it was part of the defunct THQ games that Deep Silver bought when THQ went under. Considering that they just paid about $5.9 million for the rights to both Metro games they were pretty much happy to give away the original game in the hope that people would purchase the sequel for full price. Considering that Metro: Last Light sold as much in its first week as Metro 2033 did in its first 3 months it was a pretty successful strategy.