Let's talk "false economy".  That is getting a really good price on something
but the end product is inferior.  So you wind up having to spend more on
getting it repaired or adjusted properly than if you bought a superior product
for a little more in the first place.
With transmissions this is important because they are so expensive to have
fixed and even  more expensive if they break down on the road afterwards and
you have to have them fixed by the local gas station mechanic.
Check out what the definition of "rebuilt" is with the person you are getting
a bid from.  Ask them for a list of the parts they change out and if they make
any modifications to make the trans better than original or if they keep it
stock.  I talked to one company that makes thier own 3rd and 4th gear shaft
that is supposed to be 10 times stronger than the stock one (this is a really
poor design by VW).  Therefore when you get a rebuild from them it is actually
better than stock.  Check this stuff out.  When you are spending the money
anyway, get it done right the first time.  If you have to spend a little more
at least you will have confidence that it is done right.
Thats my 2 cents.
Ken Wilford
Van-Again
John 3:16