Bear's class trip to DC

My sons history class is going on an amazing field trip to Washington DC in the spring. He wants to go so bad. He is excited to visit the meuseums and his very first airplane ride!
I am doing what I can to make this happen for him, but our deadline of January is quickly approaching and it isn't looking like we're going to pull this off.
This is an expensive trip for us and any help would be so amazing. Please help our son go on the trip of a lifetime.