I've been at this off and on since I first got one for Christmas as a kid. I'm currently at under 20 titles to go for a complete US set (licensed & unlicensed) and also have a nice sized Famicom collection. As others mentioned here the best route is through lots, and then flipping ones you don't need to grab the others. Lots of hunting at Flea Markets and pawn shops have also paid off well for me over the years. One of these days I may complete the whole set, but with homebrews and more coming out all the time I'm in no hurry and it is fun to keep hunting.

Good luck!