Would anyone that has some knowledge of Autoharps please take a look at this autoharp that is listed on eBay for me?

eBay item number#         
290845156776


http://www.ebay.com/itm/290845156776?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

It is listed as an antique and vintage. It caught my eye and I want to know if there is a way to trace the serial numbers etc. Is it worth the asking price?

Thank You for any help that you can provide. There are quite a few pictures on the listing. It is a "The New Golden Autoharp" with a Serial Number of 5317 (Are the Serial Numbers sequential?) Would that make the autoharp kind of rare? I mean would a number 5five thousand three hundred seventeen be rare if there were say twenty thousand made for instance?
Thank You for taking the time to consider my questions.
Raina