Maybe with a brand new motor, but you could get a used one and rebuild the internals if its even that bad.

Used Mercedes E55 AMG Engines > Mercedes E55 AMG Engine Motor Sales (Top Salvage Yards)

That is just an example, but those are E55 AMG motors for less than $2K. Then selling your v6 for 800, 900 for Mercedes SDS, and 1200 in parts. Those numbers are from a PM with Bob, I really couldnt see the 55K being THAT much more than the C500 Bob put in. You are talking $17,900 in parts....

EDIT: This is self install. A shop would charge a ton at current labor rates.