NASA budget in 1966* - $32,106m
NASA budget in 1969* - $21,376m
NASA budget in 1970* - $18,768m
NASA budget in 1975* - $11,131m
NASA budget in 2011 - $19,450m
*adjusted for inflation to 2007 dollar value
NASA has actually had some very generous budgets since the 80's, after the lean years in the 70's. The space shuttle program was conceived in the 70's, when the US government was saying "Okay, now what?" and the spacey-wacey fellas had to come up with an answer. They managed to get it off the ground (literally) in the early 80's, apparently suitably impressing Congress enough to wrangle some cash out of it.
However, the space shuttle has really been a massive money-sink. It was just the other week when I read someone arguing that the scrapping of the space shuttle is the best thing that could have happened to get NASA off its ass. Their budget is ample, but they haven't been able to accomplish much because they've had this fleet of big whales on the launchpads and these costly missions made up just so the shuttle would have something to do. I'm inclined to agree.
The space shuttle was designed to be reusable, but the constant complications and expenses of maintaining a shuttle fit for re-entry makes the whole thing a big funeral pyre for money. One shuttle mission costs just as much as a whole modern rocket like the Taurus, for example (perhaps a rocket that's less of a complete failure would have been a better example, but it's a bit tricky to dig up launch costs for these things). And that's just taking the single flight into account. If you take the cost of the entire shuttle program and divide it by the number of missions, it comes out to one point five billion dollars per launch.
The shuttle was a milestone of scientific and engineering progress, but it was a dead end. Let NASA and the rest go back to the drawing board and come up with a proper, intelligent, modern solution.