Wait a little before the winter sale, it will start in 3 (plus/minus) weeks

Most people are waiting for this, and all these lists of "historical low" and who bought what will mostly be then. Prices will not change much, but you will have time to save up some money, and still have time to sell cards from your inventory. Plus, if you are going to level up your Steam profle, the winter sale is the best time to create badges, you'll get an additional cards by creating them, then sell them and got little extra.
As for Bioshock, it's a good idea, but be prepared for the fact that the remasters of the first two games are incredibly bad, they constantly crash, they can delete saves etc. There are lucky ones who did not have this, but this is very rare. Fortunately, they come with old versions of games.