Remember that once you buy, stop looking for at least 6 months, then tell yourself that life with the old system would have been unlivable so the fact that the systems out now (6 months after you bought) that are 30% less and twice as fast aren't that important. Also remind yourself that in another 6 months the systems out then will also be faster and cost less. so you just can't win, be happy that you've played.
No matter how many people tell you that an A computer is great, or you must but from X or Y and don't forget to get an extended whatchamacallit and an extra doofus, you could still get a lemon. (Nope that's not a jab at Apple!) Check out ResellerRatings.com, try and buy from a company with at least an 8 or a 9 rating. Yes that tosses out most of the national chains (Best Buy, CompUSA, Circuit City, and others) and direct sellers too like Dell and Gateway. You might want to use them anyway, but check the reviews and make an informed decision.
Resellerratings also has links to current sales as does GotApex.com.
Why am I talking about this now? About 4 months ago I bought a new Laptop from InternetIshop. So far it's been working nicely, but ... I got some accessories with it too, in particular a 120GB external hard drive to use for backups. Well the drive died on me last month and I was going to call and see about getting a replacement ... Can't they went out of business. Checking them on ResellerRatings I find that they've been going downhill fast for several months. I even think the signs where there when I was dealing with them, both in odd things they did, and late shipments of the system.
Knock on wood, I won't need the now worthless extended warrantee I purchased from them, and who knows I might be able to fix the hard drive (but it was a noisy beast, so I'm not sure I want to).
Anyway, good luck and enjoy your toys! (oh a 3Ghz P4, 512 ram and free printer for $349! it's from Dell and their rating is less then 3.0 but ....$349! wow)
Stop me before I buy again!