If you like the sound and price buy it. If you’re not sure whether you can truthfully evaluate it’s condition, hire a good technician to evaluate for you, or if the price is good, take your chances.
Harps are made of wood. Sometimes there are hidden flaws. Every major builder has built lesser and better instruments, and that may not coincide with the price of model of harp. A lot of the price is just for carving and gold, which are labor- intensive.
So see if the harp speaks to you with your touch – or not.
And, if you haven’t, several reputable technicians and stores have info on their websites about how to evaluate a used instrument. There was also an article in HC a few months back, I think. I remember Peter Wiley and Carl Swanson were two of the contributors.