If you're looking for inexpensive, use a Bessa R or R2.
For a camera that has been out of production for more than 40 years, the Contax IIa and IIIa continues to be relatively expensive. A properly serviced Contax is a thing of beauty and precision.
There were only a limited number of postwar West German lenses available for the Contax -- in general, all were excellent. On the wide end, there are the 21mm and 35mm Biogons and the 35mm Planar. The 50mm offerings included a Tessar and two Sonnars (f/1.5 and f/2.0). The telephotos included the 85mm Triotar, the 85mm Sonnar and the 135mm Sonnar.
The 85mm Sonnar will cost at least $400 and possibly more. The 21mm Biogon often costs about $700. The 35mm Biogon and Planar are usually at least $350. The others will cost from $100-$200.
So, the Contax IIa is not an inexpensive camera. Excellent photographic tool? Definitely.