What kind of additional costs are there to consider?

What kind of additional costs are there to consider?
Obviously the plane tickets to Boston, and various model building supplies, but was there any major expenses that took you by surprise?

I can not think of any additional substantial costs… outside of the plane ride…
a. There can possibly be some subway (MBTA) costs… $2-$10 at the most

b. Taxi cab to and from the airport (if you don’t take the subway)… $60. Take the subway... it will take a few more minutes but well worth the time, unless you have too much luggage… then it may be a hassle but still worth it.