Ok. Just for the sake of a discussion, lets look at a couple of programs.
Specificallly: Gracie Miami run by Pedro and Gui Valente, Gracie Academy Torrance with Rorion et al., Kioto Jiu jitsu by Francisco Mansur and this guy Reylson Gracie.
All are high ranking jiu jitsu instructors that teach basically the same curriculum: Gracie Jiu jitsu. No MMA, no training specifically for sport/competition(although some do compete), just jiu jitsu as Carlos/Helio did it.
Any of these places you go and get group lessons. They are very popular schools, so it is easy to conceive that there could be 20-30 people in any given 1 hour class.
At an average of 2 training sessions a week in a group class, it's possible for brown or black in about 6-9 years.
*** Lets not fight about how long it takes to get a black belt. I beleive Marcel Feitosa of Gracie Barra has gone on record saying that 12 or 15 years is ridiculous and that some one training consitantly 2-3 times a week should get a black in about 5-6 years***
So, is it feasible(I didn't say desireable) that someone with dedication and alot of money could train 3 times a week with PRIVATE lessons and get a brown or black in three years and be legitimate. I'm not talking about a PanAm or Mudial Champion, but a legitimate rown or black???