I recently put a berimbau on my Christmas list, having gotten back into Capoeira and wanting to be able to contribute to the music. A local has offered a handcrafted one for a price similar to what shows up on, say, Amazon.com, but the pictures show it to be pretty heavily painted over the bow and gourd. I have seen it said by Mestre Bimba that "a painted berimbau had no voice" and is therefore meant primarily for decoration. Is this perhaps a matter of more modern materials changing things, or does this still hold true? Since it would be a private transaction, and he's headed back to Brazil soon, there would not be much chance of a refund.
I'm starting to suspect that this may be a matter of a combination of appeal to tradition and changes in lacquer / paint technologies. I purchased the berimbau mentioned above and I can't tell any difference in the sound from the lacquered-only berimbau I've played in class.
I think in this case your question has more to do with your own relationship to this particular instrument. May I recommend obtaining it in a more organic fashion? What I mean is I think there is merit to obtaining it of a direct transaction perhaps through your teacher or the next time you attend a workshop/seminar/batizado/roda, or of course by travelling to Brazil.
Often times these are great conversations to be had with teachers and masters that can lead to additional insight on their experience and knowledge of the berimbau, of how to string it, how to make one, stories about its role in capoeira, of songs and so on.
Just a thought. Best of luck on your journey in capoeira. It is a long and exciting one!