They are often called pests so hard to buy let alone find in pet stores but they are AMAZING tank cleaners. You can sometimes get them free if the petstore just recieved stock and have them before they are thrown away. I got 2 the other day at petco on gunbarrel but they didnt want to go picking for more even though I was willing to pay.
Also wanting a few mystery snails (sometimes comes in the live plant packs).