Go to one of the
EZ-Pass Group member states/organizations and order their pass. It's generally worth your time to compare the various fees and policies; some charge monthly or annual fees, maybe only under some circumstances, and/or offer special discount programs in their states, and they also vary somewhat in how or what balance they require one to carry in the account, how and whether they charge for transponders, and other such details.
For one example, if you have a motorhome (but not an RV trailer) and will be in New York state much, the Thruway Motorhome Discount plan can save you a decent amount of money as it cuts the tolls roughly in half, from the "tall" vehicle rate to the "low" vehicle rate.