Perhaps the manufacturer would have a good description of the difference in sound: https://manufacturing.dustystrings.com/harps/browse-models/fh36h
Personally, I suspect there is more difference from one harp to another (and one player to another) than choosing based on model or wood species. The most significant difference is how _you_ play. So, you need to play it and listen.
Considering the new cost, and that one regularly sees them listed for more than that amount, it looks like a good price. If it is a good instrument, it likely won’t stay on the market long.
But you need to ask some questions:
Does it have any structural issues?
When was it restrung? (Strings cost about $165 plus installation) When was it regulated? (Regulation is certainly needed if never done)
Is it Loveland or Camac levers?
And, most importantly, do you love the sound _you_ can get from the instrument?