Most Mexicans will negotiate with you on the price. Don’t assume that you can get something for ‘half’ of their starting price. It will depend on what you are negotiating for – a service (like a massage or music) or an item (like a dress or food) – as to how much they will be able to discount. Some work for themselves, so they can freely negotiate, others work for someone else and may not be able to go below a certain price. It never hurts to ask for a discount.
Keep in mind, at full price, most items cost less than you would pay back home. These people work HARD so be kind and considerate when you negotiate with them. The beach vendors walk the beach all day, carrying their goods – in the hot sun. You don’t even need to leave your beach chair to knock off your souvenirs for the kids back home – so consider that.