I have a question... a banded leuc has no spots, correct ? I have seen regular leucs have less spots that some of the "banded" leucs that I have seen for sale.
Banded Leucs can have a few spots. Juvie nominate leucs get more spots as they get older.
The 'Banded Leucomelas' came out of Guyana fairly recently, I believe - within the last 5-8 years ? I'm also thinking that they came from Venezuela by way of Guyana, and are deemed to be a distinctly different morph / population of Dendrobates leucomelas for hobby management purposes.
That said, like ANY other 'Hobby" animal for sale...be sure to vett the seller / breeder and be 100% sure you are getting the animal that you want /desire.