I have a 73 Bavaria that I did the automatic to a 5 speed conversion. Best thing I ever did to that car, it was transformed into a car that is really fun to drive.
The E3 3.0S model (only available in 73-74) is the fancy version of the Bavaria, it came loaded with all the luxury features, leather interior, power windows, sunroof, etc.. Finding a 3.0S in a manual gearbox is rare. Just like 2002's, the pre big bumpers (73 and earlier) are more in demand. You can find some great deals on big bumper E3's.
G-Man
91 318i
74 2002tii
73 Bavaria, 5 speed, Webers, bilstein's, E24 BBS basketweaves, etc..
70 E3 2800, 4 speed, Euro spec, totally stock