Carrier requires data package -- 29.99/month. Android OS has Google maps for free. Only other way to get device without contract and data package is to purchase device at full retail = $559.99 but will not have phone service.
ESN is specific to each device. Kinda like the serial number on your TV. It is not only on a label on the phone, it is actual programmed to the device. Try to resell the device to recoup some of your money if the vendor will not take it back.
The most important decision to make when considering cell phone service is the network. Will it be there when you need it? The next thing to consider is how are you going to use your phone. Do you NEED or just WANT all those bells & whistles? If you get a smartphone/Blackberry you are likely...