Bradley,
Just my opinion.... When purchasing anything on e-Bay, you should research the seller's credentials and even then, you never know exactly what you're going to get till you get it.
In your situation, especially since this is going to be a business machine, you'll want to make sure that you have "support" for the machine, (or machines), that you purchase. You'll want to verify that all of the recovery CD's and software is included with the purchase. That's not always provided with the e-Bay stuff. If something goes wrong, you'll want it to be fixed without a hassle or have the option to take it back for a refund. If I'm advising for business purchases, I make sure that local and reputable sources are used so that easy support is available.
If you watch the sales advertisements in your local paper, you can find most brand name computers at fairly cheap prices and they will be for sale close by. The small amount you save is never worth it if something goes wrong. Your time alone can be worth big bucks.
Hope this helps.
Grif
I'm new to computing and have posted to forums only twice. I received excellent advice and was able to solve the problems as a result. I'm back for some general advice.
I want to purchase new hardware for my business and want a good buy on a brand-name computer. I need a good internet system with storage for databases and room for standard business applications, ect., and would like to have fast multimedia capabilities. I've been looking at Dell 8400s on Ebay. They appear to be suitable to my needs and budget.
My question is however, are these systems cheaper because they're outdated, stolen, broken or some other reason? Are the sellers legitimate? They seem to be. How are they able to purchase at a price and sell for much less than the manufacturer. Any information or recommendation is greatly appreciated.
Thank you!!!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic