They're both ancistrus. They tend to act the same and grow the same. I also believe they can be bred together, but I don't know if they are exactly the same fish
Normal BN and GBA both get to around the same size. If they grow to 100cm, i'm probably screwed with the 20+ I own :lol:
IMO, $32 is way too much. You can get young ones on TM for around $6. Well, in Auckland you can