Dear jj6143... during the 30's and 40's Indian as Harley made many models. To play with these old motorcycle you must be a kind of "doityourself" biker. Generally the less you pay for a machine the more work to be done you will have. A 1940 sport scout, chief or four have a lot of difference in term of value. It's impossible to put an "average cost" on  such a large inventory of motorcycles.(please excuse my too precise amount). If I ask this:" What would be the average cost of a running ford car between 1960 and 1980"? You will ask me a Pinto? or a Mustang super Cobra Jet 429 Boss? $50.00 for the pinto And $250,000 for the Mustang. The best for you is to check carefully the model you would like to own and after come back in this forum and let's talk............Alain

The latest Stark's "Smoke Signal" has approximate values of different running Indians.  You can also look on ebay to see what various Indians actually sell for.

So have you figured out what your working on? What condition is the rolling chassis in? Do you have a picture?

If there not any broken fins on the engine and everything is rebuildable you should propable budget around $3000-$5000 for  GOOD quality rebuild some nickel plated or chromed parts and mechanical upgrades.