Thanks for all the info, fellas. It is appreciated.
The local computer shop has an Intel Core Duo E7600 (3.06GHz) for $127, which is the same price as Tiger Direct's E7500 (2.93GHz), so I'm going to go ahead and get that for an CPU upgrade (it is compatible w/ my MB as well).
The same shop also has the ATI Radeon HD 5750 for $105, which is $10 cheaper tha nTD, so I'll go for that too [unless I hear Darth Vader howl out "NOOOOOOO!!!" hinthinthint].
Thanks again!