So, I'm new and I have a few cool looking pets others might want to breed with, any ideas on how to set a fair price?

There's not really a site-wide system people use for pricing unfortunately. People tend to use the number of visible traits and overall appearance as a kind of guide - more traits generally = more gold. :)

If you're curious you could use the advanced search to look up pets similar to the ones you're thinking about setting up to get kind of an idea of what others charge. If you select "Order By: Breeding Fee" you can see the cheapest ones to the most expensive ^-^

Feel free to ask if you have other questions!