The last few I have seen on e-bay in good running condition went between $65 - $85. They are a well built saw, not the fastest but have good torque. The P41 and larger are the more sought after saws. Parts can be a little difficult to find for any of the Pioneers. I would try to find out the compression. I would offer $50 and see what happens, good luck.
Not sure what they are worth , but pioneer makes a darn good saw . I have a p38 that was my father's, had the exhaust baffle taken and re jetted . Things a beast,