If it is priced according to its condition, it is probably rough. Of course the turfs drag the price down. 1920's did not have a factory R-4 tire option. Figure $3500 or more to put R-1's on it unless you know where to get a full set of used tires and wheels. There are three combinations of front/rear R-1 sizes; be sure to match the correct fronts and rears if you get that far.
Without knowing more about the condition, it's impossible to say whether it's a good deal or not. Make sure it has a sound clutch, and the front axle has oil in it and makes no rude noises.