Like has been said anything is only worth what someone is willing to pay for it.

But it also has to be said that just because you spent a lot of money on a car - it doesn't mean it is worth that total cost to another person.

If you bought a set of vaders, spoilers wheels etc - someone probably made a profit from you on each of those parts when you bought them. It was worth it to you to spend that money to get the car the way you wanted, but it might not be worth it to the next guy.

When dealing with the likes of a 318is then I think you'd really have to be looking at what you could buy the ultimate E36 coupe (M3) for - to me logic would say that there will be no 318is worth as much as the cheapest E36 M3 (nct'd and running OK.). Even when you bring the travesty that is the Irish road tax system into it, it would still make more sense maybe to just stick the 1.9 engine into an M3 if a 318is was what you wanted.
I mean we all make our 318is' look like m3 anyway....

Bottom line I guess though is if a car is not selling for an advertised price then the market doesn't think it is worth that.