I guess I have a set of less grim suggestions.
1. Make friends with an audio junkie and get him/her excited about this project. Be prepared to buy a meal or two. Being able to use all their fancy, expensive gear makes audio junkies feel all warm and fuzzy inside. How do I know this? …no comment.
2. Talk to the FOH person. Sometimes these people have their own gear and like to make recordings of the live shows they mix. I know of at least one venue in the San Diego area that makes cheap recordings of live shows available to the amateur musicians as a way to make a few extra dollars. You can always re-mix it in post. Just make sure you capture a set of stereo placed room mic(s) so you can get the live venue sound in post as well as everyone on stage mic’d. The only thing you’ll probably have to watch out for is drum mic’ing, but you’ll see what I mean quickly. In fact, a couple cameras placed stage left and stage right with on-camera mic’s would probably get *you* close enough to the room tone.
A good live mix isn’t easy. Please don’t try to do it in FCP. ;-( See solution #1 above.
S.