Need QUICK help! Which Mac Mini would you buy?

[y2flyy]

Guy on Craigslist selling a Mac Mini 2.0 ghz (purchased in March) with 4 gigs of ram for $500
Or buy the Mac Mini 2.0 ghz brand new from Apple Store for $550 (Tax Free weekend, Student Discount) with only 1 gig of ram

I am buying only to use as a HTPC with plex (no multi-tasking). Is 1 gig enough? Or would you all buy the 4gig model?

Please help I have about 30 minutes to decide....

 

[Hellhammer]

I would get 4GB one because it's cheaper

 

[geoffreak]

Make sure the one on CL has a 9400m.