The street hat seller appeared in the doorway of this art gallery. I saw the wonderful shadow and was able to snap 2 photos in quick sequence, before he realized, that I am not buying anything.
I did not buy any of the wonderful paintings, (High quality work, by-the-way for $300-$400), but I did buy a hat the next day. ($4).
Most paintings in the tourist shops were of dubious quality, but 1 or 2 galleries displayed really good stuff, for reasonable price.
You can only legally export a painting from recognized gallery and with a receipt. But I do not think, they really care.