Hmm the problem with this type of thread, is that a car is going to worth different amounts to different people....depending on what they want/are looking at from the car.
Personally, when I choose the car I want I'll buy it and then not keep track of how much its worth because its worth more to me as the car that I've chosen. And as this forum is predominantly not a forum to sell cars, I'm not sure how reliable the source of info is going to be. OK, so you will have people on here that have probably recently bought cars that could share what they paid, but dunno whether that's going to give you an accurate representation of the 'true value', not to mention that that information is also publically available to you through looking on autotrader etc.
I've recently decided to sell my GTI so looked on Autotrader/Pistonheads/Glass Guide to find a rough valuation, but at the end of the day, its got to be worth it to the potential buyer. If he/she can justify the cost for the age/milage/condition/specification then so be it....
I'd call it an 17.5K car personally .... but Joe Bloggs who comes along next could say its a 14K car because he thinks because it has no nav it is useless....
There's no problem with posting this thread, but I'm just not sure how much 'value' you're going to get from it, and i hope it doesn't confuse you even more. Its ultimately worth what you think its worth, given the research you've done on the market at the moment.
Get a Glass guide and see what they think, I'm sure someone on here will be able to help you out with access to one.