Christi is right that there is one official rate. I have never seen it..... Oh occasionally you see pictures of the tourist boards with the official rates from the cruise piers and such but never the real deal that would let you figure out what the fare is from the zones.
However, some driver try to charge 2 rates (or 3 or 4....). One for people who look like they live there and one for those who look like they don't and don't know any better. I know I have overpaid from what those more experienced pay. It isn't an official tourist rate, but rather a 'you don't know better rate.' I had a guy once try to charge us 300 peso for two points in El Centro. The missus straightened him out in Spanish. We still paid more than I was told the 'official' rate was, but it was alot closer. The few times we use a cab, I just try to figure out what the rate might be and settle for anything close. I guess, to some degree, it is just business. A member of our group time didn't listen and went to a touristy shop and paid like ten time more than he should have for a blanket. It happens.
However, some driver try to charge 2 rates (or 3 or 4....). One for people who look like they live there and one for those who look like they don't and don't know any better. I know I have overpaid from what those more experienced pay. It isn't an official tourist rate, but rather a 'you don't know better rate.' I had a guy once try to charge us 300 peso for two points in El Centro. The missus straightened him out in Spanish. We still paid more than I was told the 'official' rate was, but it was alot closer. The few times we use a cab, I just try to figure out what the rate might be and settle for anything close. I guess, to some degree, it is just business. A member of our group time didn't listen and went to a touristy shop and paid like ten time more than he should have for a blanket. It happens.