I'd go for it. When you consider what it can do, $40 is pretty good, assuming it's not completely beat to hell and the screen is good. Plus, you might wanna keep a spare phone around in case something like this happens again. I always keep at least one spare data dependent phone in case my primary goes out to safeguard my unlimited data. Worst case I'm sure you could get at least that on eBay or one of those trade in places.
Just checked Verizon trade-in & Gazelle. Verizon was $26, Gazelle was (I used a middle of the road condition for everything) was $16. I'd still bet you'd get more on eBay, since you're selling to the end-user, not someone who was to recycle it or resell it to someone else. Either way, if you go the Verizon route, It'll cost you $13 to get you by until the Inc4G drops. If that's 2 weeks, that's not too bad. The further it's delayed, the more you value you get out of it (assuming the $26 price holds).
I say go for it.
EDIT: Just checked eBay, the lowest Buy It Now is $19.99 (with a cracked screen), after that it's $70 & higher, some for parts, the lowest usable (with scratches) is $75.