31 spline 8.8 w/ disks, 4.10s, complete. $400
lock right 250
gears (if needed) 150
brackets (depends on suspension) 10-50 bucks (if it's for a TJ or something similar, find a throwaway TJ housing and hack off the bracketry--cheap and easy)
setup 150?
chrome diff cover. 50
You're obviously more concerned with cost than strength, so go with a lock right instead of a detroit. I'd go spool, but I just like simple and reliable things--I'm weird like that.
If you do the work yourself, you can have an 8.8, w/ 31 spline shafts, disk brakes and whatever else for less than 800. If you have to have someone else do the work, add a couple hundy to that (unless you get buddy/beer-pricing). Even at 1000, it's worth the extra 200-300 bucks to have the better axle. Besides, the super 35 kit gets pretty expensive after you have to swap out bent housings, blown R&P's etc.
I'm in my 31 spline 9" about 400 bucks including gears, spool, rotors/calipers/brackets/brakelines, etc. There are better solutions than a super 35 kit. Not trying to be a dick or argue with you, but I've never spoken with someone who purchased one and was happy about their investment. I'm come from grand cherocar circles, and those sissies will try anything to avoid 'swapping axles'.
What vehicle is this for?