I can get you a brand new aluminum driveshaft, any length, from Coleman Racing for around $225 shipped. This includes 2 new 1310 "U" joints, but no slip yoke. If you have the big 1350 "U" joints, it is about $100 more.
I have an account with Coleman, so I can get you dealer pricing. I am not sure of the exact cost today, but I got one for $205 shipped about a year ago, so I am adding something for inflation...
aluminum driveshafts are a no-no on anything over 400 hp and over 3000 lbs.. if it was lighter then you might be ok but i did the same thing in my firebird a few years back and it cost me a tail shaft and some floor pan repair.