Driveshaft Center Bearing? R32 Gtst

[CanadianGTST]

So I was fiddling around under my car the other day, putting a catalytic on for emissions testing, and decided to see how much up and down play my driveshaft has. Much to my shagrin, it has at least 3" of play when pushed at the center bearing, maybe a bit more. I was always under the impression that the clunking on shifts was a result of too much backlash in my diff. Seems I was wrong, it's the driveshaft flinging around like a bastard! I'm not sure how much play is standard, but it sure as hell couldn't possible be 3+ inches.

I've also read that too much play in the driveshaft can cause one wheel peeling, even with a good diff. I can only spin one tire, there is zero lockup what-so-ever. My question is this: What should I expect to pay for driveshaft work? I've never had it done before on any car, and I'm kind of fearing it's going to be expensive. If it's expensive enough, I'll get a one piece aluminum shaft made instead. Does anyone know if a mechanically competent guy can DIY the center bearing?

Damn these old cars, damn them to hell!