I'm no expert either, but many argue whether the Virgin Brazillian that's sold by vendors (AV's & CV's) is really Virgin Brazillian. It's been rumored that vendors are really offering Indian hair, chinese hair or a mixture of both that has been processed.
The argument is that a good majority of Brazillian women pride themselves on beauty and hair and would not dare cut their hair. If this is true, Brazillian hair would be in limited supply...so i too would think that 100% Virgin Brazillian hair would be crazy expensive because of the limited supply. You may want to do a little research on the Brazillian women and their culture in order to draw a conclusion for yourself. I've not had much luck finding a vendor/exporter in Brazil, lots of vendors in China that sell Brazillian tho'.
The one vendor I did find (about 5 years ago) that was out of Brazil and had a rep in DC (can't remember the company's name). They sold what they called virgin Indian hair. Ha! Not even Brazillian hair. They sent me a little sample of their weft (about 2 inches) and the hair quality was very bad.
Regardless, ppl still love them some "Virgin Brazillian". Me too!