in my area (probably a couple of hundred miles from you) theres no way a stock banshee would bring 4k. i would have trouble selling mine for 4k and its a 4 mill cub.
You can start at 340 but you're probably gonna wind up around the 300 range. 280 is probably gonna be a little too lean though. Start at 340 and buy some in between sizes.
tim steele has a nice white bike with black wheels
check out his sig in post #3 in this thread
http://bansheehq.com/forums/index.php?showtopic=155416&pid=1349067&st=0entry1349067