Totally agree, don't skimp on the PSU, but for what he was mentioning a good $50ish one would be just fine. I'm amazed at how the Computer market has swung. I remember when the CPU and Memory where the Killer priced parts. I just looked at an old box of PC part receipt and had 128 ram stick for $300! the 700MHz Intel CPU was $400. Nowdays the CPU is $200 and the ram is Under $50 (even cheaper if you not going hog wild). But MB prices are $200+ (many cases $300+) and Video cards!!!!!! a new one every 6 months at $3-500! that is, if you believe the hype.
I build systems (not for a living, but as part of it) maybe 20-50 a year and I have built everything from "so cheap its Fisher Price" to "I can almost run Crysis with all options on" depending in customer.
To many people eat hype like candy, there are allot of "good" parts for decent prices out there, PSU are one of the weak spots in many systems now days, 3 video cards, OC'ing, giant fans all over and people think a 750 watt PSU that costs $50 is going to do it because its 750Watts. The average system (Quad core CPU, HD, DVD, 2 HD's, couple fans and a 260Nvidea video card (or something close) should pull about 260-350ish watts depending on load. A "GOOD" PSU should be ok at 75% load so a 500Watt PSU should last a long time. many PSU are rated at 80% nowdays. There are always exceptions to the rule. I had a 700Watt corsair die on me, and I have a 8400wofldale (oc to 3.9), 2 DVD drives a 8800GTX and 2 HD's in a case ($30+shipping) I bought from Computergeeks with the CHEEPO no name 400 Watt PSU that has been running it (non stop) for over a year. I keep forgetting to swap it out. I DO NOT re comend the cheepo's, its not if it will fail, its just when, I'm living on borrowed time right now I'm sure, but just never think of swapping it out until I'm actually using the computer and don't want to shutdown then.
Sorry for the novel length post, just hate to see people thinking a $200 PSU is required, or a $600 video card. There are cases when High end equipment is needed, but for Mame machines, average gaming its just plain silly to spend $1000+ and find out in 1 year you can get 2X the speed again for the same price. those $500 video cards that are top of the line today and in 6-12 months you can buy for $150... I guess if you have the money, why not, they tell us it will help the economy.
Clok
By the way OP, let us know hoe it all works out.