I think its important to realize that prices, and even a fair price, can be different depending on what part of the country you are in ...
like with the paintings that are sold all over ...they tend to be very similar ...a small one at the only gift shop in Monte Cristi where there is hardly any tourism might be $5, whereas something of similar size and style in Cabarete or Santo Domingo is going to be more, even after some bargining. I think this tends to go for the non-touristy stuff too ...food, drink, household goods, clothes, etc.
A lot of times I don't even try bargining for stuff around here because I know its much cheaper at the given price than it would be in other areas ...and I like to support the local vendors here that don't get nearly as much business as would someone in Santiago or Santo Domingo, etc. Here, CDs and DVDs (burned of course) are about 40 pesos w/ out bargining ...the fake designer sunglasses that are sold everywhere, about 70-80pesos ... a pedicure sans the fancy salon- 40 pesos!, braids- 50-100 pesos, a huge painting (maybe 3 ft by 3ft) cost me $25 US last year w/ out bargining ....
I pay these prices without bargining here and when shopping for similar things in places like Cabarete, SD, etc I usually get a good price by 1)speaking in fluent Dominican Spanish (I think this is half the battle in itself), and 2) refering to the price I would be paying for the item if I was in Monte Cristi ....the last time I needed a pair of sunglasses in Cabarete the price started at 900pesos and went down to 450 ...I walked away to visit the other shops and in passing a second time I ended up paying about 150 for them.
One thing I don't like is to see people browse and or bargin with the jewelry/cigar vendors on the beaches if they have no intention of buying. If you intend to buy a necklace at some point on your trip, then by all means browse away, but I've known people who didnt have money on them and/or didn't intend to buy, waste these vendors' time. That annoys me.
For anyone who really enjoys the bargining scene and/or wants to test their skills- make sure to head to the market at Dajabon on Monday or Friday ...you can get some very cheap Dominican goods. Nice jeans, tops, cheap jewelry, sandals, belts hats, handbags, etc ....last time I purchased some nice mens jeans for 200pesos ...