You know, DF was close to having a legitimate gripe, but he completely blew it IMO.
Theoretically, Ultracade is in a different market segment than companies like emdkay.net, mamemarquess, Dream Authentics, etc.: These companies serve hobbyists like ourselves, while Ultracade produces arcade machines for COMMERCIAL use (which, if you think about it, makes sense as to why their machines cost so much more...you can legally charge for play on them). Even if you're in the market for a MAME machine for yourself (whether you want to build one, or whether you want to buy one off of eBay), you're still in a different market than the one that Ultracade targets.
The utterly frightening part of this is that Ultracade is trying to - at the very least - get money from these companies...companies that, again, service an entirely different market. That's when they've gone WAY over the line. What a jerkass.