Advice/Help needed: WIFI dead+unactivated+<7day warrenty

summary picture, calendar with timeline:
http://i37.tinypic.com/4r92s0.jpg

8 gig original iphone. I bought it off craigslist and found it had a bad usb port :(
Luckily, called apple and they replaced it under warranty.
Got it back, but never activated with AT&T, jailbroke/activated with pwnagetool and then quickpwn for 2.1 but wifi worked sporadically and now never. It looks like the wifi problem is unfixable and I cant afford an iphone plan so it will be activated. I've heard you can make it a go phone or something but isnt it still quite costly?

What do I do?

TL;DR: my wifi is dead on an unactivated iphone and the warrenty is almost up.

I'll monitor this thread constantly, I don't know what to, please tell me.