I can't even begin to come up with a number. There's things I am doing because of FT I never would be able to do (Rome for $250 in Feb for example) so while that's a huge savings, it's also something I wouldn't do without the savings, so it's not real money to me as in money made.
But money aside, the value is totally in the people and knowledge, which can't be quantified (nor explained to outsiders).