AVOID LIKE PLAGUE the electronics shops on Flagler Street in downtown Miami. Unless you know exactly what you want - and how much the item costs elsewhere - you are going to be subjected to an unbelievable and hostile harrassment from the salespeople in these shops.
WORSE, a lot of the equipment sold there is REFURBISHED, with a very limited warranty, at the price of new! Do not expect to be told if anything you buy is refurbished - it's only in the fine print of the invoice that you will be asked to sign.
FAR WORSE, the prices are not even competitive, I just bought an HP laptop there for US$1300 and found out the same item (refurbished) was available for under US$1000 from reputable vendors on the Web.
In other words, Flagler Street is just good enough to buy digital cameras and other cheap equipment, provided you are willing to haggle lots and be very careful. Not recommended, AT ALL!