The main drag just off the beach, Avenida 5, has been closed for pedestrians only and is overrun with restaurants and gift shops. The street is the life blood of Playa's tourism.
When you get sick of shopping, Avenida 5 is great for people watching. Sit in a cafe or just camp out on the plaza. Local women sell cups of fresh fruit, while taco and juice carts set up around the plaza where locals buy their breakfasts and lunches.
Prices are on par with dining out in New York City, no kidding, and the food ranges from decent to spotty. (See restaurants). The other thing to do is shop, and you can find a really lovely selection of Mexican crafts, and junk. It all depends on what you are looking for. The selection of weaving, pottery, silver and gemstone jewelry and decorative pieces is definitely better than what you’d find in Cancun, but the prices are still pretty high.
You can get lots of silver and amber here. The silver is touted as a great bargain but I think its mostly a rip off. I did see some unusual opals -- wild multicolored fire opals, and firey orange cherry opals that I've never seen before and covetted, but did not buy.
The stores on 5th Ave were not too keen on bartering but would offer a meager 10% discount for cash in pesos. Go off the avenue for some better deals. My weakness is pottery: I found two pottery shops just off 5a on Calle 2 that would engage in some mean bargaining, and I found a better quality and variety of craftsmanship. Look for the nightclub Crocodilo on the north side of the plaza and go into the craft market on the ground floor.