The banana gene has plummeted. But I still think you'll be able to get a couple hundred for single gene animals. I think they'll hold their price better than some of the other single gene co-doms simply because they are so striking in appearance.
And triple gene animals are tougher to price IMO. Especially with newer combos like this there aren't as many out there, so not really a set market. I would price him at what you think he's worth and go from there. If he's still not sold in 3 months, then probably too high, if he sells in 3 minutes, possible too low, or you just found the perfect buyer at the perfect time.
But first I would worry more about hatching healthy clutches before pricing imaginary hatchlings. Don't want to put the cart before the horse.