the other option is to go the old carburetor route.  my local 
vw mech-a-bud is always proposing that i replace my brain with
a carb.  altho the gas mileage may suffer a bit, i'm not getting
much better than 17 in my '78 2000cc, so i doubt that i'd lose 
much if any.
i replaced my brain about five years ago for around $550 new,
so your quote is probably on target.  i've never tried the old
junkyard route, but it sounds like that is a viable option. 

oh yeah, and when i replaced my brain it was because i was 
experiencing similar herkie-jerkies to what you described.

may you rumble again soon!!      

andrew