In case you builders out there saw the latest dog pile on the Y! group, I have a few thoughts:
Droid building will cost money. Going to conventions will cost money. Doing events for charity will cost you money. Things will break and cost you money. Upgrades will cost you money. Being part of the builders room will cost you money. Your wife will continually remind you that R2 costs you money. Nothing you can do will ever change the fact that this hobby will cost you money.
If you want to travel around the country to hang out with your friends, don't expect (or demand) to do it on someone else's dime. Doubly so if you don't even have a completed droid.
On a more positive note, check out some sweet Star Wars money by Mark Brooks