I just too a quick look around and seen them start as low as $30 and go up to $200 if your a new breeder you won't be able to get as much as the veterans
Most I see are $40-$100 for adults unless you're a very well known/respected breeder. Then you may get more. I've seen some at shows for around $40-$50 though.
Depends a whole lot on health, quality and your knowledge of their genetic background. Like others have said - $30-$50 if you don't know a whole lot about their background and more if they're from a high quality line or a respected breeder. Also depends on where you're selling and to whom.