During my last 2 recent trips, I routinely paid 100 to 120 pesos with Apollo taxi (fare plus tip). I think they charge RD$90 as a flat rate. I've gone from Maximo Gomez to the Dominican Fiesta (about 6 miles) many times on that rate.
Of course, hotel taxis are to be avoided if possible. Whether from the Fiesta or Courtyard Marriott, I get hit for RD$300 if I use a hotel taxi. Since the peso has appreciated, that's now a stiff $8 bucks one way.
In early August, when the peso was 44 to 1, a 120 peso taxi fare translated to $2.72 Now, at 37 to 1, a 120 peso payout is $3.24. If you take 5 or 6 little taxi trips a day like me, that difference adds up quick over a week.
Be careful if you ask the driver to stop temporarily when taking you from point A to point B in the city. One time, I had a taxi driver stop for 5 minutes while I went into a colmado to buy a few items. I came out and hotel taxi continued on the destination, but tried to tack on another 400 pesos for a 700 peso total fare. That was a blatant ripoff.
But, some taxi drivers (greedy ones) want to argue that is another fare, because you made them stop. Again, I've only had those situations with the higher priced taxis from the major hotels. Ask the driver beforehand to avoid surprises. :squareeye