Think there's a big difference between what a MK2 is worth and what people think it's worth. I keep an eye on classifieds on different forums and have seen 16v 3 doors in seemingly excellent condition struggling to sell for much over £2000 and 8v about half that (there is currently a lovely small bumper 16v 3 door for sale on the Golf MK2 owners club for under £1500 with no interest). The worrying thing is that the owners forums usually represent the top of the market.
I have an 1985 3 door GTI which I was hoping to put up at about £1500 when finished, but it's become obvious that even in top condition, I would be dreaming to expect that much (luckily I've only spent about £300 on it!). For my valver, for which I have a full project thread, and is now in excellent condition, I wouldn't expect much above £2500.
Parts are no better - there are some bits which are quite hard to find in good condition, but they are few and far between. That said I had a mint 5 door rainbow interior with door cards (and I mean mint - the bolsters on the driver's side had been replaced with low mileage passenger ones) up for £170 and it took 6 weeks to sell at that price. I still have a full room of parts in my house that I am struggling to give away.
The market may recover, but at the moment it is pretty bad out there if you're trying to sell.
If you think we have it bad, I just picked up a Corrado VR6 which had been on sale for 4 months, starting at £2500. In all the time it was up, I was only the second person to even view it (the 1st had agreed to buy, left a deposit, and never came to pick it up!). I bought it for HALF of the original price listed. This is a car which has had £2800 spent on it in the last 2 years.