Replying to Just got the red ring on my xbox

So exactly a week before modern warfare 2 comes out my xbox decides to shit itself after 2+ years. Any other time I would be cool with waiting 2-3 weeks for the repair, HOWEVER that's not an option right now. My xbox still has the warranty so I can send it in for free and get it fixed. This leaves me with two realistic options:

1) Send my xbox in and buy a new one at walmart or wherever for $250. When I get the fixed xbox I can just sell it online for $200ish. This will leave me with a brand new xbox with 3 year warranty for a little over $50.

2) Just fix it myself. I looked up guides online and it's pretty easy to do (I work a lot with electronics so I know my shit). I'm pretty confident I could do it with no problems. I fix pretty everything by myself, however a free warranty is obviously the safe choice.

What have other people done? I've heard stories of people buying xboxes and then returning them when they get theirs back, where can you return an xbox you used for a month (if I felt inclined to do such a thing)