It's kind of sad to think of how many thousands, millions even, of P. imperator have been taken from the wild over the years, and now that their collection has all but stopped, they're rare in the pet trade.
I'm glad that the importation of wild caught P. imperator has stopped.
In regards to breeding the 'rarer' species; this is probably part of the reason that P. imperator has become so much harder to find after the ban on wild collecting. Everybody wants to keep and breed the latest rare species (including me) and the bread and butter stuff carries on being taken from the wild and sold to beginners for cheap. All it takes is for a country to ban collecting of species X Y Z and suddenly something that was so common but overlooked by 'experts', 'breeders', 'pros' is on its way to disappearing from the hobby altogether.
A lot of the rarer species aren't really 'imported' in comparison to how P. imperator and other common species are i.e. it's not normally some profiteering exotic animal dealer who gets hold of the rare species that appear in the hobby. When I think of the word import I think boxes upon boxes of animals, whereas with many of the less common species that are kept by enthusiasts, it's often 1 or 2 of the enthusiasts themselves who have gone out and collected a small number scorpions to create a breeding colony. The offspring from these then slowly filter out into the rest of the hobby. I think this way is much better than buying mass collected scorpions. It's vastly less damaging to the wild population of a species, it gives more of a value to a scorpion (not just monetary), it lessens the impulse buys as it takes a deeper interest in scorpions to want to keep a generic 10mm long 2i sling knowing that it will eventually become an impressive adult Parabuthus spp., Pandinus spp., Iurus spp., or whatever, rather than wanting the instant gratification of a big, black scorpion right here, right now!
Anyway, I'm not sure where I'm going with this and am waffling!!
My advice would be to try and find some P. imperator if you can. They're great scorpions to keep. As Collin said, they'll probably be slings if you do find some for sale. What country are you in?