depends on the size, and availability in your area. In my area (washington, dc and environs) they usually go for about 12.00$ for a quarter sized fish or 2 for 20$. RBP's in the 4-6" range are around 50$. Monsters (12+) are like a bill i think...
if you're set on pygos, and you have any access to other pygos I'd say get a solo caribe. I just like em better but they're gonna be like twice as expensive at least i think.
oh yeah and check the legality in your area. P's are illegal in some states.