They aren't exactly common to come by, and I've only seen them in my LFS once I believe. However, it really depends on where you live. They're really nice fish though if you can get your hands on some.
You could try asking at your LFS to see if they'd have any way of ordering them in, as some shops provide that service. If not, buying online is a good option Or you could start out with a similar tetra that is easier to come across.
I don't know how close you are to Wales you are (I know Chester is pretty close) but The Green Machine in Wrexham would probably be a good place to visit if you want them as they're the kind of fish that look great in planted tank.
I've got 42 P. simulans in a planted four foot and they're lovely; I was lucky, my LFS (in Cornwall) usually has them in. I've been building up the shoal or about a year now.
yeah i got 6 of these the other day from my lfs in cornwall (homeleigh fluttermoth??) and since getting them i have had nothing but problems? i think its these lovely fellows attacking my lampeyes and shrimp. they are curremtly isolated to see if there are anymore deaths if no more deaths before friday then they are going back to the shop
i thought that aswell but its the only thing that fits. part of me is hoping its not the fish as i love there colour and look really good with the lampeyes but like i say so far its the only thing that fits