Recently there have been some REALLY good deals with Siege @ eBay....
BRASS Kong II's, Viair 380, 200psi, 3gal, COMPLETE Kits for @ $160.00!!!!!!
If you win one of these, Siege is Happy to "upgrade" the tank from a 3 to a 5 and a 3/8 valve to a 1/2 for very little extra so you end-up with a hell of a package for around $200
(that's just about what they get for the Viair 380 ALONE)