Dpends on size, locale and garantees. Mine was purchased for $39.00 at 2" long, but there are a lot of royals in the area, and many of them sell for less. I took the expensive one for a multitude of reasons, but primarily because it had been at the LFS for 45 days and was still very healthy, which meant it was indicated an excellent specimen that was not prone to disease.
Try aquabid if you can't find a good one locally.
dave
Although I like the Ancistrus catfish because they breed easily. (I just got 2 new breeders yesterday!) My favorite is corydoras. I never kept them until recently but they are always cleaning or playing. Besides who could not like the way they court each other! Too cute!
Royals are my favorite too. I got mine for $28, but its a Dull-eyed(L191, black and green w/ dark eyes). I can't any other kind in my area. I saw a L190(brown and black w/ red or orange eyes) once, but it was $50 for a 2"er w/ no guarantee. Had to pass at the time.