Ebay of course
Pump it Up SX W/MK3 (Came with PREX1 installed) :
Before I ended up buying this machine I made an offer and I do happen to watch ebay often so here are other items that went by while watching this machine and others :
Pump it Up Exceed 2 GX Starting Bid : $2,500 End bid $3,000
Pump it Up Premiere 2 SX BIN : $5,500 Offered : $1,500
Pump it Up Premiere 3 SD : $1,900 (someone purchased this over the SX I got... WTF)
Pump it Up Exceed 2 GX : Starting Bid $2,500 End : ???? (someone on PH got this... hear it required quite the cleaning job too)
Pump it Up Exceed 2 Upgrade kit with MK6 : Starting Bid : $150 End Bid : $610
Pump it Up Premiere 2 Upgrade kit : Starting Bid $200, Offered $150 for this and got it.... thats whats in the machine now.
and tons more stuff I've come across like a Dance Maniax machine.
There are a few machines on ebay right now :
pump it up, Arcade items on eBay.com
Shipping from out of state is $500-$700 depending on the company you use
Don't take those three older machines to really be that price. The key is communication with the seller (no one in their right mind will pay $5,500 for those older machines) So you can make an offer and communicate with the seller to see if they're willing to let it go for your offer price. I lucked out and got something with no problems at all... but be sure to ask the seller if there are any problems with the machine. If the auction states it's fully working it better be.