I play a berimbau for Capoeira. One of the most fragile (and most expensive) bits is the cabaça, a hollow gourd used as a resonator.
I'm not very familiar with the qualities of the resin used for 3d printing. If I were to take this to our local Maker Lab and have them scan and print a copy, how likely is it that it would work? My fear is that the plastic would be too sound deadening.
If you want a less exotic parallel, imagine the body of a guitar. That's a resonating chamber.
Following up on this, the answer is, yes, this works quite well. I printed this cabaça model from Thingiverse using PLA on a Lulzbot Mini and put it on my berimbau today to test it out. I can't make a direct comparison because the printed resonator is smaller than the gourd one that I own, but the sound is good. I am not certain whether it is actually cheaper (it used a fair amount of PLA because it's probably about a half-inch thick, and it took a few tries to get a good print due to it taking about 9 hours and needing to be monitored for the filament breaking), but it may be more accessible for people who can't ship a gourd in from Brazil. It is definitely more durable.