I used to a lot as a kid. It was pretty much the only way to get some more obscure games.

I pretty much stopped in the mid 2000s except for some collectors editions of games that I was 99% sure were going to be great Halo3, Fallout3, New Vegas etc. I still do the same thing now with the odd switch collectors edition xenoblade chronicles, the final fantasy pixel remasters, unicorn overlord but those were games I was 99% sure would be finished at launch.

The rest of the time I wait a year or so until the game is half priced and finished.