After a bit of investigating, and calling around, it turns out these turbos are Chinese manufactured copy-cats of the original. The company that sells it is Rothenbacher Engineering of NC, apparently the parts they sell are awful and have lead to many catastrophic engine failures for many Merc/Audi/VW owners. I think its very clearly worth paying the extra $200 for a MetricMotors rebuild!
'86 500SEL 43k miles-sold
'82 240d#2 200k miles simply beautiful
'80 300SD 184k miles "Sheikh Diesel"