My first car was a Mk2 1.8 GL, aged 20 with zero no claims, it cost me about £1200 to insure with Norwich Union (through Endsleigh).
The 1.8 GL is a fine car with a decent engine. I once raced my mate who had the same engine in his Rocco Scala, and he beat me, probably cos of being slightly more aero dynamic, although that was only really effective over 50Mph.
When you do your quotes, try the usual tricks:
* add parents as additional drivers (especially if they are over 50 with many years experience) even if they wont drive the car
* insure it at a good/safe address (Elephant will let you insure it at a home address so long as you tell them where you keep it overnight)
* see what difference having an alarm/immobiliser will have on the premiums
Have you tried the specialist insurers? Ones that either specialise in GTIs/VW or ones for young drivers?
Try Adrian Flux and Brentacre.
Overall, I'd say buy yourself a decent Mk2 driver, don't pay over the odds, keep it in good running order, save your money, then when you can afford the insurance sell the Driver, and buy a GTI.