As far a monetary value.. they're not worth a whole lot. Burm morphs tend to lose their value relatively quickly because of large clutch size (80 eggs or more isn't unusual) and since they grow so large, not as many hobbyists keep them.

I believe you should only keep species that truly appeal to you as a herper.. not those that carry a nice price tag. Are they 'worth' getting? Well, if you're prepared to care for a snake that can reach 100lbs or more and live for 20 or more years.. then go for it. Burms are fantastic snakes for the right person.