Correction: You have two w123's: one is a 300TD and the other is a 300D. A sedan is not called a 300TD, only a wagon is.

A rebuilt transmission with warranty costs less than your asking price from Sun Valley Mercedes Transmissions. Your prices exceed the value of what most people can buy a complete, running car for. Most people on here are looking for bargains, and it's doubtful you'll find any buyers unless you cut your prices AT LEAST in half