Ive been trying to decide on what to buy for my first car.

My options are loosely based on this list:

240D (manual everything perferable, and 83-85 also)
300D or 300D Turbo (83-85 perferable)
300SD
1968-76 BMW 2002( Ive been waiting for the owner to get the title for over 2 weeks) I dont think hes going to come through.

I really like the 300SD, although I would think that parts would be more expensive which is not a good thing for a 16-17 yr old.
How do the prices in parts compare between the 240/300 to the 300SD? I have looked online, but I cant be sure since I can only base it on things like injectors.

How is the shifting with the 240D manual? Like a truck or refined? This is the only thing that I am skeptical about.

My father thinks the 240d manual is the best bet. ( I think hes right from a economical point of view)

Ive been trying to decide for a long time now, and im still stumped. I figure with a luxury car like the W123, and W124, bigger is better since high performance isnt expected.

I figured I would ask for your opinions here, since most of the members have owned more than one MB diesel.

Theres a 1980 240D manual windows and trans 150 miles away going for 3k, and I think thats the most logical decision, but I am not sure about the trans.

Theres also a 300d non turbo with "97k mi", and a clean 300SD.

Thank You