The value of an animal always lies in the person spending the money. Compare all the different examples of the morph you want to add and select the one that best represents the ideal you are seeking to breed. You will pay more to buy from a big name but that doesn't always mean they have the best looking snake. I've made some fantastic deals negotiating prices on snakes that I have found to be top notch examples of their respective morphs. I've paid under market pricing on many snakes in my collection. Find the snake you want and then negotiate a price. Any other way of doing it is setting you up to spend too much or to get a snake that is a poor example of the morph. Just some advice for you and welcome to the board and hobby!
Regards,
B