I guess if you break it down, it's about $210-250 per coin, and the mintage on all of them, especially the mouse, ox and tiger is very low
Only suggestion I can give is to try and find how much they have sold for separately recently, and use that to form part of your valuation
I just spent 10 minutes looking around, and from what I can see most of those coins are going for well over $200 USD, which would lead me to think that his asking price seems very good
Might be worth sending a message to people who know a lot more than me though lol
GL