Although I don't have a tutorial, or any advice, I just wanted to post a link to another N64 "Power Pak" - The "64Drive".
http://64drive.retroactive.be/I can't speak for either this one, or the Everdrive, but I'm told the "64Drive" is the one to get. Faster loading times, and more compatibility - according to their site, it plays 99% of all the games. I know there was a thread talking about the two somewhere (Nintendoage?).
Only thing with the 64Drive is that you're looking at (at the minimum) like a month or two for it to ship, as the guy custom makes them.
As for the price, these Power Pak's tend to run from $175-$200, so you're right, they are a bit pricey. But realistically, the SNES Power Pak goes for about $145, so it's not that much less...
Satoshi: I find it hard to believe you'd be able to pick up "every single N64 game that's worth playing" for under $200. Then again, that's all subjective too, right?

Depends how many games you feel are worth playing, and how rare those games are...
Anyways, just wanted to add my 2 cents.
