Hi Dan!
Excellent question!
IMHO some good starter chameleons would be either Veiled's, Panther's or Jackson's. Unfortunately any of those species don't really stay small. Male Veiled's can reach a maximum length of 24", although I've rarely seen one that long. Panther's are about the same. Male Jackson's will maybe reach 14" full grown. There are dwarf Jackson's that reach a maximum length of about 8", but are very, VERY hard to come by.
As for availability, Veiled's and Panther's are becoming very prevalent in the pet trade. Jackson's are a little harder to find, but not impossible. Obviously prices vary in different markets, but on average Veiled's are $75-100, Panther's are $150-200 and Jackson's are $200.00 and above.
Certainly there are small size chameleons on the market, but I wouldn't recommend them as a good starter cham. Their daily requirements are a little more exacting than the above mentioned species. Because Canada is still a small market, some of the weirder chams are still coming in wild-caught and their price tag is much higher.
Click
here for a Veiled care sheet.
Click
here for a Panther care sheet.
Click
here for a Jackson's care sheet.
Hope this helps!
Trace