The price of a kitten depends on the breed, demand, supply, geography, and the number of surplus kittens the pet shop or the breeder has to feed.
Prices can be higher on the coasts.
Prices for exotic or new breeds can be higher. Unless you just have to have a certain cat. Kittens for show will vary in price due to breed, demand, and potential. Persians tend to be higher. Remember, the more competitive a cat is likely to be, the more you can expect to spend.