Masquerade and Saboteur combined could get your 2 cost Bridges out of the trash for a while, assuming your opponent helps by gaining the Bridge for you, then passing it back.
e.g. 2 opponents, I Procession Bridge twice, Saboteur revealing 2 6-costs, they gain the Bridges back, and I Masquerade them slowly back to my hand. I can Procession the Bridge twice more, play a Highway, Saboteur revealing two Colonies, they gain the Bridges, and I pass them back to hand again.
So that's 4 Procession'd Bridges plus a Highway used for 9, with 10 Bridges, 9 Highways, and a Princess left. King's Court chain to 10 KC'd Bridges for 30, 9 Highways for 9, a Princess for 2, and the Upgrade itself for 1. 9+30+9+2+1=$51.
I haven't even used Band of Misfits... I'm sure there's a way though.