you have to get them from from ORA, so It depends on what whoever wants to charge for them...
I got a pair for $120 from Absolutely Fish about a year ago when they didn't know what other people were selling them for elsewhere. I had a choice from about 6 of them, but i have not seen them there since.
saltwaterfish.com sells them for $99/each last time i checked.
I had a pair but i lost one to a jumping incident. Unfortunately the coolest looking one jumped. I paired the remaining Picasso with a "normal" ORA bred percula recently.
also, not all Picassos are created equal. For example one can be really crazy looking while his brother from the same clutch only looks slightly different from a normal percula. So it's kind of a crap shoot if you don't see them first. And the really cool ones usually fetch a hefty price, like the $400 ellebelle mentioned. However, i think ORA charges the same for all Picassos, and vendors are really taking advantage of the craze as of late. Again, I paid $60/each a year ago...So the mark up is insane right now. Not worth the price if you ask me.