TravelTalkOnline Forums Travel and Vacation Forums Cancun - Isla Mujeres - Mexico American Dollar OR Peso's

We haven't been to Mexico since 1993. I've asked a few friends who've gone to Mexico in the past few yrs, 50/50 on using both.
I remember it was best to use US dollars when haggling on items. Now I don't know.
Should we be getting Peso's and small American money?
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