The Best Buy outlet has a refurb 250 GB slim right now for $150. If you don't have much cash right now buy that, get your free month of Gold when you register an account on the system, and then buy a year of Gold for $40 (if you even want it) when it goes on sale in the next 4-6 weeks as it often does. Add a used/sale Kinect for $100 or less when one becomes available, again only if you want it. It's a much better deal and you'll really be glad you have that hard drive. I wouldn't worry about the refurb's 90 day warranty aspect. With the heating problem solved if anything goes wrong it's likely to be in the first month or after a few years.
Hmm. I think I may jump on this. My 60GB 360 died last summer and I've missed out on all those great XBLA games (the only reason I owned a 360 in the first place). Thanks for the tip!