They could, but it's not likely to do them any good. It wouldn't be wise for another team to give up any of their money. They keep them on a very tight budget, and they wouldn't want to run out, themselves.Can a team borrow money or beg money from another team?
Can a team pay the cab/bus/train fees for another team?
And borrowing wouldn't really work - because it's not likely they're going to have a lot of extra money on upcoming legs. And then, what would happen if that team were elminated next - they'd never get the money back. I think it'd be too big of a gamble to happen.