For one game, I guess I threw down around 300 for my 3rd sculptors cut. I spent 600 on a cib n64dd with f zero expansion cib. 650 for my nintendo employee jacket, mug and controller set. 300 for my m2000.
I've paid £50 for an N64 game from time to time, back when the games were new. I don't think I've paid more than that for a new game, and I'm certain I've never paid more than that for a used game when I was looking for rarer games in later years on ebay or the 'net.
Proud to say that the most I've ever spent on a single game was 25SGD (about US$18?) for a sealed copy of Conker's Bad Fur Day in 2007. Back then I didn't really think much about collecting and I opened it just to play the cart... no regrets though! I only ever buy N64 games that are cheap and I find the whole collecting experience more fun that way (being a broke student back then and now helps out with that too). I did spend 200+SGD on a 64DD though to celebrate the first paycheck I got from the army a couple years back but that was a special occasion for me haha.
Wow, looking it up now I had no idea Second Attack went for that much. Didn't think there was that much demand for it. That's sad, Bomberman 64 was one of my favorites as a kid and I never got a chance to play the sequel even though I always wanted to.