So I took a 4kq driveshaft (not great condition, rusted) to a shop to get balanced/cleaned and they called me back saying that it will cost $590 to get rebuilt, not counting the CV ends. I then asked if it would be less expensive to just shorten my existing 89 90q driveshaft (good condition) to the 4kq length. They said that's not possible because of the weld type used on the driveshaft, fuse I think?

This is new territory for me, does this sound correct to you? Thanks