Wait for the upcoming major sales starting with the autumn sale and then winter sale. Most games will go on sale and you can expect to see a lot of 50% off sales on steam at that time. Might as well start to build up your wishlist in steam for the upcoming sales.

And to add to that, it is not only steam that gives sales. There are 3rd party websites that also introduces sales for games such as fanatical and greenmangaming. There are also bundles websites which could easily increase your library of game.