There are no rules for pricing a kitty for sale. Sell your kitties for the price YOU think they are worth. There are so many different opinions about pricing a cat for sale.
If you have a look at the secondary market you will see, that there are many different kitties at different prices.
Some people think that a kitty with a lot of traits is worth thousands of lindens. Some people sell their kitties about 150 lindens to cover their breeding costs.
Maybe stroll the secondary markets and have a look for yourself. And then decide what you think is suitable for you.
Welcome to our wonderful kittycats world.