I'm building one right now from the ground up for my nephew, tired of riding by myself. I personlly prefer to start from frame-up. I don't want to buy something and then take her apart. Cheap banshee's that I've seen around here are still going for $2500 + and most of those are as old as an '87 like mine. Being able to purchase almost 99% of the parts on ebay make things very convienant, I've believe we can build her for around $1500 basically stock. Once we have her ridable, then he can upgrade parts as he can afford it. He has $350 in parts now such as the axle, wiring harness w/cdi and coil, gas tank, front and rear shocks swingarm and a couple of other small items I can't remember. He's about to get the frame off of ebay for around $275 with shipping. And doing it this way once he has all of the frame parts we are going to have'em powdercoated.
Time flies, gotta go take my boy to T-BALL. I will check back later to see if you post any questions.