Is the rattle from the turbo CHRA or the wastegate valve?

If it's a worn out bearing on the turbo the shaft will wiggle when you try and move it with a hose off. In that case you can order a pre balanced CHRA (center housing rotating assembly) which is a fancy term of all the important insides of the turbo. Mellet in the UK make good stock replacement ones for a couple of hundred bucks. No idea what labour to install would be but it won't be $4,000 and I sure as sh$t wouldnt be visiting a VW $tealership after warranty for anything.