BCI are more common, easier to care for (smaller and aren't as demanding of husbandry requirements) and less expensive.

Surinam is BCC.. colombian is BCI. Hogg island boas are also BCI (I recommend these guys! they're so cool!)

A captive bred colombian boa is around $75, more for an extra nice looking one.

CB hogg islands are usually around $150-200+

BCC are the most at $200 (low end) up to $600 or more.