Penny, bear in mind that buying a used instrument on Ebay is like rolling dice: you won't know what you're getting till you see it. Older autoharps may need re-felting and most likely will need re-stringing, and there's also the possibility that some of the keys may not work properly, or even that the wood may be cracked. (Don't trust the description to be thorough -- the seller is trying to sell the thing, after all!) Even if the seller accepts returns, you will probably have to pay for the shipping to return the item... and then you will have spent money for the autoharp's round trip without having an autoharp to show for it. Buyer beware!

Your best bet is to deal with a reputable music shop, where the proprietor will repair a used instrument before selling it and where you can go to try it before buying it. Otherwise, you may want to resign yourself to buying something new.