Therea are among the easier of the hobby roaches IMO. They just have a longer development time than some, though this is greatly sped up by warm temps and a protein rich diet.
I just started keeping them for the first time, and they're pretty neat. Definitely one of the more underappreciated "pest" species (I mean they're really all underappreciated except for P.americana).
Well Blatta orientalis are invasive, but if you mean house pests no, they tend to only infest sewers and other very moist areas around human habitation, rather than houses themselves.
Most of those are Blattid nymphs, probably B.orientalis. However the nymph in the first pic on the far left is a Parcoblatta. You can tell because the last abdominal segment ends in a single point rather than being cleft.
Huge difference in supply and demand here in the states, keepers have struggled to produce this species as consistently as those abroad have due to any number of reasons. So the price remains very high here because the supply is far less than the demand.
Also I would argue that the EU hobby had...