Second time traveling to Budapest and have been reading all the great information. We will be arriving in Budapest on Sept. 12, and I would like to take a day and go to both Szentendre & Estergom but questioning if I should start in Szentendre and then somehow get a train or bus to Estergom or do I do the opposite way? I would like to travel by boat back to Budapest in the evening so do I purchase the ticket when I get to the city? We will be staying by the Market and I understand I need to get to Batthany Ter and purchase tickets.
You train to Esztergom and then take a bus to Szentendre, then the boat to Budapest. You can purchase the boat tickets at the bottom of the boarding platform about an hour before departure http://www.mahartpassnave.hu/en/timetable/danube-bend-excursion-boat-lines/budapest-szentendre/
Esztergom has a z in it or it would be Esh ter gom