Something else to consider from a care perspective is that because boas eat less frequently than pythons, they are cheaper to feed and require less day-to-day maintenance for cleaning. I've had retics flood their cages with pee every day for 2-3 days in a row. Adult boas tend to go every 2-3 weeks.
Also consider the cost of feeders. I'm lucky enough to live at the edge of a rural/suburban boundary so the local farmers know I'll take culled chickens or rabbits, or stillborn goats/lambs/pigs/etc. as giant python snake food. If you have to buy those feeders and have them shipped it gets very expensive compared to feeding rats.