You have a blown engine. Drop a good used cheap five cylinder turbo under the hood and save a lot of money. It wil be far from cheap to get a 616 four cylinder engine up to the same power and usability levels as the turbo five cylinder.
Use the transmission as well with the replacement engine if yours is an automatic. The turbo transmission is stronger.

Plenty of wrecks with decent power trains still out there. You want the rear differential and speedometer head as well. The ratio is too high on the 240ds rear end.

Basically should be a bolt in with a little luck as the chassis are the same on all 123s. I did mention a lot cheaper as well than what you mention with a little scrounging. Where you are living is like here in that there are rusted out bodies with good power trains out there.