This is something I hope the devs adress, a 'max acceptable' button for the money slider. I can't think of a good reason not to have it, it get's boring to get to the exact number and after a while I just drag and end up losing a ton of money due to laziness.
I mean, I doubt that when Thomas Jefferson got his eye on the Louisiana Purchase, he had to sit at the diplomacy screen with the french and say '5 cents an acre? 6? 7? DAMN YOU TELL ME HOW MUCH YOU WANT YOU FROGS!!!!" Well...yeah...basically. Got a bit too into that there, but still.