If the item is DOA (dead on arrival) the seller might say that it was working when they shipped it; that you messed it up. You might get scammed, as well.
I buy all my computer parts from newegg.com, which has the best or second-best prices and great customer service.
What's the budget for this build, and what will you use the PC for?
I have not yet built a pc but would like to try to do it with used inexpensive parts from ebay. I currently have a P3 800 so my next computer would be a P4 of some sort. I would like a suggestion as to where to start. I'm scared about incompatibility issues since there are so many products available.
I would go for an AMD chip even though i've owned only intel up to this point. This would be my 5th computer since 1992.