Lolz, Hatterasguy on this board has a MK3 Jetta- he hated it.
I think he got an abused model - if the one you are looking at has been taken care of, $1k isnt a bad price (I bought a 1997 Jetta GLS (all options except the big engine) for $2k a year ago)
Stuff to look for in MK3 vw's (MK3's are the golf/Jetta's sold from 1994 to 1999)
timing belt - every 100k.
Expect to replace an alternator, one or both half shafts, and water pump between 100k and 150k miles- every VW's I've had suffers from this.
Parts are more expensive than american car prices, but not much more than japanese car prices.
good MK3 VW tech help page
VW MK3 wiki
Your 96 will be OBD1, if its the "2.slow" ABA 4cyl, 8v with 115hp, you'll get 30mpg if you baby it, 24 if you beat it. My '97 has this motor and it does the job ok but doesn't rev real high and sacrifices a lot of top end for midrange (which is nice, but not "sporty".
The other engine available is the 2.8l(?) VR6 - 6cyl - good for 170hp with horrifically complex timing chains and more expensive parts with added maintenance nighmares - I recommend against the VR6 unless you are vw guy who has to have one (300hp turbo VR6's are not unheard of)
There is a large aftermarket for these vehicles and motors - plus, they were VW's best selling models so junkyard availability isnt bad either. expect none of the build quality that you see in a W123 however. My 240D spoiled me compared to the VW's that I had driven for my entire life.
There is a forum called
www.vwvortex.com - which, other than the kids, has a lot of good info on it (you just need to filter out the stupid kids comments =)
All in all - not a bad car- I chose mine becuase of its price and I know how to work on them. Not as overall reliable as a jap-o-box, but workable and plenty of aftermarket if you want to go that way.
-John