Where to buy system?

Newegg
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Just an example, not reccomending a refurb, but for $264 what do you want?

You can get directly from a company like Dell (www.dell.com) or even from a vendor like Newegg (www.newegg.com).

Are you looking for a single system or multiple systems?

www.hp.com

www.dell.com

www.newegg.com

www.tigerdirect.com

Just to name a few popular, reputable sites.

Well sometimes with dell computers if one hardware component fails, then the entire motherboard must be replaced because the hardware parts are not replaceable. Sometimes with dell computers video cards can not be removed off from the motherboard.

Please list a store or a system that sells systems with replaceable hardware parts.

For the prices you’re quoting and the system cannibalization issue, I'd go with HP. We have been using them for several years and canning old systems for Hard drives and memory. We don't usually use dedicated GPU's for desktop publishing/ data entry, which is what the majority of our users do.

If any users needed CAD (we have system architects that do) we got them stock D400 or D800 workstations. But I am limited to what’s on GSA.

I suggest Costco. They offer a second year of warranty free and a 90 day return policy, no questions asked.