It's tough to properly ID a specific species w/out seeing the shape of the teeth, number of fin rays, etc. Given variable color/pattern to blend in w/surroundings, the same fish would look quite different on a darker, single-colored substrate. That looks like one I picked up along with a used tank some time back. I had no desire to keep the fish, and took it to the lfs for ID. I was told it was a common pleco.
The common pleco's are mass-produced in outdoor ponds in Florida. If the price was low that's likely where it came from. Imported or even tank bred "exotic" pleco's are generally quite a bit more expensive. The common BN is the exception, they're so plentiful the price is comparable to common pleco's.