Carnivore fossils are the most sought after by collectors and the most difficult to obtain. Of the carnivores, cat fossils are very desirable and highly sought after. To help better understand why carnivore fossils are so uncommon, just think of the African plains today. There is a pride of lions about 15-20 individials strong hunting wildabeest in a herd that is tens of thousands strong. Most cats are solitary in nature so the perfect scenario has to take place to have that cat die in the right circumstances for it to fossilize. The odds are overwhelming for any animal to fossilize, let alone an animal who's population is fairly low to begin with.
Carnivore fossils are always a good investment.