Be sure to pick up an 8 point tuner tool. Pluck a string and tune the peg until the string is in tune. I should tell you that fine tuners added to any autoharp will give you more precise tuning and save hours of tuning time. A. Its been my experience that autoharps don't increase in value much with age like guitars and other instruments. Antique shops may be able to help you with this matter however they seem to sell for a lot less than we paid for them.
Old ones are nice to hang on the wall or donate to museums for displays.
There are more expensive brands that also work well if you want to spend the money. I clip the microphone on my shirt close to my heart and hold the autoharp snugly against my chest. Plug the microphone into any amplifier. You can also play the autoharp into a standard vocal microphone but I find it hard to play without hitting the microphone with my fingers. You don't need specific music for the autoharp.