common. thats an interesting word. yea like joefish has basically said, there are a lot of "commons", such as hypostomus punctatus, hypostomus plecostomus, glyptoperichthys gibbiceps etc etc... i believe whole heartedly it is a glyptoperichthys joselimaianus (and are commonly called gold spot plecs, given L numbers 001 and L022 before described by science). they seem to be sold as commons or incorrectly labelled as Glyptoperichthys gibbiceps quite a lot. On price, i think you did about right or quite good, my current one cost about 12 GBP. oh, by the way, your other one looks a lot like an adult liposarcus pardalis (or hypostomus pardalis) but im not 100% i'll have to have a look. funnily enough though, liposarcus pardalis is also sold as a "common pleco".