Hey there! Sorry, I had a rough morning so I haven't had the time to sit down and reply, oof. Anyway, to address your concerns, rares are a type of rarity! It's like, when you click a pet, it shows the rarity of the pet depending on how many people got or own that outcome/pet. Second, lists are a kind of thing members made that incorporate both rarity and demand. "List pets" have a much higher value due to the enormous amount of people trying to own them. Third, shops are for Chicken Dollars, or C$. C$ can naturally be obtained by paying real cash, but many users can also get C$ from other users who pay them. c:
What's your ign on CS? Mine's f1owercrown if you want to hmu there!