Unfortunately, appraising a clock is something of a trick business. Condition is everything, not only for the movement but the case as well. Also a service history (much like an automobile) can add much in the way of value. The other major factor has to do with where you are located. the further away from large metropolitan areas, the value diminishes.
Having said that, judging from this picture AND if the clock is in good running order (accurate timekeeping and chiming correctly) then a reasonable starting point would be about $500.00. Now, that is what the clock would sell for from a dealer who simply had to clean and service the clock before resale, with no other repairs needed. So, you are looking at whatever the market will bear in your area. I hope that helps you.
