The dwarfs from Nicaragua don't have documented wild populations either. Collectors have been finding them somewhere recently, though I hope this isn't one of this species last refuges.
I don't mean to be rude, rottbo, but your comment was insensitive and selfish. I don't know if you read Animal Mother's post or not, but to reiterate this animal is not suitable for aquarium life as it is right now and likely as it will be for several years to come. Wild populations are unknown, and while you may be okay with endorsing taking a possibly endangered animal from its natural habitat and shipping it several thousand miles, just to have it die (earlier than it should have, no doubt) after a couple of weeks sitting in an LFS or someone's unsuitable tank I am not, and I urge to become more informed so that you may think the same way. In an aquarium - even one that is designed with a muck inhabitant considered - this animal will be shy and not perform any of the magical things it does in the wild, save possibly a few; that's if you are lucky enough to get one that is not about to reach senescence.
In my opinion, animals in which wild populations are unknown should be illegal to collect or kill until the near-exact numbers are assessed and released to the public. The only exception that I would support would be for scientific research.
Let me go at it from a different angle in case you are still confused. Let's imagine that we were in the big cat business - for show, fur, food - I don't care. Would you go after the Amur Leopard, if one somehow became available to you? If you are a reasonable individual you would find it absurd to purchase an animal with such a low wild population (estimates of 25-34 in the wild), despite the price and obvious health risks (remember, we are in the big cat business). Or what about a Siberian Tiger, which is less endangered than the Amur, therefore a more logical choice for poaching or training? I don't think you would go for it, although it is an awesome animal. What I am trying to get at here is just because we have the means and availability of having such an incredible thing in our houses does not mean that we should.
Maybe you just don't care about a dumb octopus because "What kind of damage can just one do anyway? It's already been collected, and I have a more suitable home for this poor guy instead of the critter keeper he is sitting in at the LFS." Well let me tell you why this line of thinking is not the correct one. You buy the Mimic at your fish store. He dies in two weeks - bummer - but no surprise if you are educated (which if you bought it I hope you are not). You tell your buddies at the fish store that yours dies and you would love to try another one. They push their suppliers to collect another just so you can have it die again in two more weeks. Other people that frequent your fish store saw the octopus and want to try one too. More pressure on suppliers. Suppliers realize they can make a lot of money off of these rare, sought after animals. They up their prices to the distributors, but the distributors don't do any additional markup than they previously were doing. After a few months suppliers can no longer find Mimics or Wonderpus, and move on to another "hot" item. Meanwhile, back in the US, consumers are depressed that their $500 octopus didn't last longer than a month, and they never saw it because it never came out until night, and it kept crawling out of the tank and almost dried up a half dozen times, and it ate all their fish, and terrorized all of their corals, and now they have to replenish all of their cleanup crew, but because all of their livestock was already destroyed, they decided to get another, and then another, until they finally gave up. Then 10 years later suppliers find another collection hotspot and start to import them again for another month until one of their final refuges is torn apart and almost every octopus was taken from it. That is what has probably happened to the little zebras from Nicaragua and the Pacific, and what could happen to Mimics and Wonderpuses if naive aquarists impulse buy or don't care about the environment once they are educated.
I don't mean for this to be an attack on you rottbo, but I hope that a lot of people get to read this and will start questioning if they ever see an animal like this for sale. If there is no demand for something, it will no longer be supplied.