I think this is a good topic, but it misses the elephant in the room.
In two ways.  Firstly, it's over *peanuts* of money at the federal
level.  I don't think it costs a "lot" to spend a few megabucks a year
to get data back from the heliopause and beyond.  Not on today's money
scale established in Washington.  *It's just not that much.*

And secondly, look at the military money going into Afghanistan and
Iraq (among others).  What's *that* cost?  What's the cost/benefit for
that?  Well, what's the benefit?  Vs, any scientific spacecraft out
there is extending our boundaries and we need all of that we can get.
If no "benefit" today it's a sure bet for tomorrow.  As vs that
military thing which costs us yesterday, today, and for two or three
generations to come.

Grump.  ...Martha Adams