For the price, I'd buy a new one. Matter of fact, the busa is a cooler bike but it's outdone in power by the 2012 to current Kaw ZX-14R. Get that if you're looking for the top hyperbike.
It looks doubtful Suz will ever improve the current Hayabusa. If you need any more info on that, check out
http://zx14ninjaforum.com/forums.cfm?conferenceid=3856F3B6-1372-66AE-3B11303B4076051F
The busa is a better bike than the Gen1 ZX-14. Never rode a Gen2 ZX-14 and doubt it's much different in handling than a Gen1 but it is heavier. It makes a bonified 190 hp at the wheel stock. Throw pipe on and you got over 200 hp. Wheelies like a mofo in third gear.
I'm feeling the burn coming on. ....