Yeah, I used to fall into that trap myself. But nowadays I usually code systems first and when everything is up and running, then I asset search to my hearts content. I spent probably a full day looking for the right music for my game at the end of the jam because I had done most of what I wanted to do (also used that "spare" time when I had finished the systems to tweak most of my graphics). If I had of started that polish stage earlier, I inevitably would've spent more time than I had doing it and ended up not actually completing the game.