I know that people have mentioned that they are relatively hard to find and more expensive, but it seems that a lot of people still seem to have them.
Besides questions of legality (you're not supposed to take the corals outside of the country, or even collect them domestically without a permit), you rarely see acans in stores here. Only sites online that list a huge collection on an "feel free to order, but expect to wait a long time" basis tend to have any. One LFS near me has one very beautiful acan, but it's in the "not for sale" tank.
Also, our acans are usually advertised not as "lordhowensis," but as other species. For example, I am thinking about buying this:
http://www.petballoon.co.jp/item/viewItem.php?prm=CE046 and it is listed as "hillae." (I also suspect mislabelling in Japan when it comes to English names at times, but I am never sure what to think.)
However, following this thread has made me wonder whether the Acans that we buy in Japan are even Japanese Acans to begin with. I'm sure some of the illegally harvested floating around on our local Yahoo auctions are true Japanese acans, but I generally prefer to buy from people who can be held accountable. Most stores here don't list the origin of the piece, except sometimes you see, "Okinawa produced" stamped on a more expensive soft coral.
It doesn't seem to matter for most people here though.