Your best choice would be Pleurodeles waltl, they are CB, they are not expensive, and they are incredibly easy to keep. If you are into big amphibians, axolotls are another great choice.
Any Triturus sp., is also an easy, pretty safe choice, but might be a little harder to find.
If you allow me to say so, i´d recomend staying away from wild caught animals (which means staying away from petshops), because although they might be cheaper, they also might be a big problem, since they sometimes are ill, highly stressed, full of parasites...
Take a look around the For Sale section of this forum, i´m sure you´ll find some of those species at a decent prize.