It costs money to buy a Kitty or breed Kitties. There’s also a small ‘gas’ fee paid to conduct transactions on the blockchain.
Buying: When you buy a Kitty, there’s no standard price. Users choose their own starting and ending price when they create an auction for their Kitty, and the price goes down until the Kitty is bought or the auction ends. Once an auction ends, the Kitty stays for sale at the final low auction price until its bought or the owner cancels the auction.
The CryptoKitties team releases a new “Gen 0” CryptoKitty every fifteen minutes. These Generation 0 Kitties started it all! They are born from the “Kitty Clock” and they have no parents. Only 50,000 will ever be created — collect them before they’re gone! The starting auction price of Gen 0 Kitties is determined by the average price of the last five CryptoKitties sold from the Kitty Clock, plus 50%.
Breeding: Every time you breed your Kitties, there’s a birthing fee. The birthing fee is collected by CryptoKitties, but it doesn’t go directly to us. It covers the cost of writing your new CryptoKitty onto the blockchain. From time to time we adjust the birthing fee to match current conditions in the Ethereum network.
If you choose to Sire a Kitty from the Marketplace instead of breeding two of your own Kitties, you also need to pay a Siring fee, which is set by the owner of the Kitty you choose to Sire with.
Gas: Transactions are secured on the Ethereum blockchain, and it costs a small fee for its miners to process the transaction. This ‘gas’ fee applies to every transaction in CryptoKitties.