He already bought the Dell, and tbf most of these OEMs are now using Gold rated PSUs or better. I have an HP with a 400W platinum and that's more than enough PSU for anything you can officially put in a SFF machine. I have strapped a GTX 1070 to it in the past and it held up with a quad core Xeon equivalent of a 6700k. Considering the OP only wants this for a work only PC doing essentially accounting and booking work, it's more than enough.Me ether. Why would they do that, unless the power supply cannot handle the power or something like that. Remember, company's that build computers are more prone to using as little as it can handle. That computer could have a psu of say 400 watts and not even 80. It may not be able to handle another drive. They build cheap for the most part to make as much as they can. Last one i bought was a Compaq and it couldn't get out of its own way. Dells are usually better but just so. I wouldn't buy the hp. If you have the knowledge, i would build your own. It may cost the same but you can buy better parts and put it together yourself. End result, is a better computer and less money or same price, Just my 2 cents.