The biggest is Gerrhosaurus validus, which reaches 30". Zonosaurus maximus, a semiaquatic lizard almost reaches the same length. The shorter G. major bottegoi can exceed both in body weight. G. flavigularis (very often G. nogrolineatus is mixed up with the yelow thorateds these days) can reach almost 18".
I do not know anything about extraeuropean pricing-but housing costs excedd anial costs by far, so I think this topic is less important.

Ci@o

Ingo