When using taxis motocouncho or just buying something never except the first price. Plan on walking away most if not all the prices will change. You are not being cheap this is the way it is here. If they can cheat you they have no respect for you they think you are stupid. Always ask for the price up front before you get into a taxi. You will find the price for you is different than the price for a Dominican.
The people here are the kindest and most generous in the world but have been spoiled by over generous people that visit from other countries who think they are helping.