Free wifi
Mikaso
Hotel is quite expensive, considering it's way off the beaten path closer to the santiago dock than most of the other places listed, but the coffee is only 5q a cup and you can use the wifi free on their terrazza overlooking the lake.
Cafe Cristalinas
For coffee lovers try Cafe Cristalinas. Not only do they have free WiFi, but also an internet cafe for those who do not have computers. The to eat menu is limited, but the coffee is roasted on site. Ask the staff about when they roast their coffee and and an explanation of the process.
Jarachik
The restaurant Jarachik also has free WiFi for those who buy something to eat. They have a very friendly staff, and great food.
pricing
The prices in most of food stores, everyday consumables, have fixed prices. Fixed prices may also be found in the public buses chicken buses. However, stores and street vendors selling art or craftwork expect people to engage in bargaining. Arriving at an agreeable price is simply part of the process, and you congratualate yourself on your bargaining abilities. The same holds true in the market place in San Pedro, and indeed throughout Guatemala.
However, not all prices are subject to bargaining. For example, hotel rooms, and shuttle buses. All hotels and tour companies must register their services and their prices with INGUATE, the national tourism board, and must pay taxes based on those prices. Remember, the business owners are no different from other business owners around the world. They have loans to pay off, investments to recuperate etc,. Remember, "Act locally, but think globally."