Here's a used one on Ebay...

http://www.ebay.com/itm/DAP-99-W210-...bbe352&vxp=mtr

That's if you want to roll the dice on a used one. New, they're fairly expensive.

This one includes TB and appears to be in slightly better shape:

Mercedes E320 4MATIC Intake Manifold with Throttle Body MB25 | eBay

You could sell the TB and recoup some costs.