Why would anyone buy isopods? They are freely and abundantly available almost everywhere. The rocks and other flat objects in my yard, for example, shelter large numbers of them. I could possibly collect several hundred isopods in one night.
Yet they are also available for purchase. I was ordering a buret* from my favorite supply company Ward's Natural Science earlier today when I noticed that they were selling a "package of 45" living pillbugs for $25.25 each. That is 56.1 cents per isopod. Rather expensive for so common an animal.
You don't even get a full identification; Wards gives the name of their isopod only as Armadillidium sp.
The only time of the year when isopods disappear mysteriously is when the upper soil temperatures are near or below freezing. So, I suppose if one desperately needed 45 live isopods in the middle of a cold winter—and if one had extra cash lying around—one could buy them. Otherwise, go out and collect your own. The common species one is likely to find in one's backyard are not that difficult to identify anyway.
*What I intend to do with a buret will probably be the subject of a future post.