You make a good point as well. The thing is my computer is 5 years old and even though the games I do play (if at all) aren't graphics intensive (games like portal, puzzle games, LIMBO, etc.) I feel 1) shame at having an older computer even though I really know nothing much about them and 2) I absolutely hate letting a good deal pass me by. I was told that my i5/ASUS combo deal was unlikely to go for less than $280 in the forseeable future and probably not less than by even $50.00 over the course of the next year, so I jumped in (although I still have not opened the packaging).
Apparently, the benchmarks show the i5-3750K is 200% to 300% faster than my current computer E8400. Not that matters if I am not using the power effectively. However, I am a longtime advocate of upgrading one's computer (if reasonable) because of the profound difference it makes in one's daily life.
For example, I have a friend who has a 6 year old shit-computer made by THE shit-company (i.e. Apple), and I told him that getting a newer shit-apple will dramatically enhance his daily life over other things such as newer car, clothes (he's fugly), or certain foodstuffs. He bought a newer Apple with Snow Leopard and was like "Wowza!" in terms of the increase in his general happiness. So I kinda guess that is what I hope to achieve as well.
p.s. I will say in a related note, I bought an expensive gaming mouse some time ago and it has made a profound difference in how I surf the web. Much faster and efficient than using the old manufacturer's throw-in.
1) What shame? Older systems will work just as well as a new system. If you have a E8400 system already, you could pop in a used Q9550 (see if you can find one around $80-100) and reap the benefits of a faster quad-core. I'd be more proud of an old, well-performing system I built, rather than a new pre-built.
2) The deal is OK, but it's not rare. It's been at that price all year, and when the next generation comes out, you'll find an equivalent deal. There are no such things as deals of a lifetime when it comes to computers, because tech you don't need is money that goes to waste; it depreciates. Well, unless you get it at 50% of retail, but what you pay at MC isn't close to that.
3) The most profound difference you'll see is a SSD upgrade. A Q9550, or even your E8400, is more than powerful enough to handle everyday tasks.
4) Once again, you're buying for the sake of buying. If you want a good upgrade path...
Buy a SSD and install a fresh copy of Windows, and defrag that old hard drive
Buy a Q9550 and throw it into your current computer if CPU tasks are slowing down your computer
Buy another 4GB of RAM if you're getting RAM limited
Buy a video card if your computer is slouching in games
Finally, if you need to scratch your consumerism itch, buy a nice aluminum case and throw everything in there
If you need a SSD right now, the Intel X25-M 160GB is around $90 after rebates on Tigerdirect, or wait for a 840 250GB to get back down to $150 again (it's $170 right now on Newegg). Either one of these will give you a HUGE improvement over a CPU upgrade.