The right parts cost, can you dont look like you want to pay for them so there is no wonder why people put them back to stop. For example if I was to look at mine:
12 plate 35K miles. 12k?
Cosworth kit 3.5k?
Ohlins 1.5k?
App BBK 1k?
Two sets of wheels 500?
Hayward and Scott Exhaust 500?
Stereo 200?
Tomms rear lights 200?
Scroth Harnesses 200?
Cosworth baffle this would never be worth taking off.
Full Siebon lip kit. (cost a packet new)
The car in bits stands as 19k+ and I think you could get more for the bits if patient. Doesn't sound like many would be willing to give that kind of money for a prepped car.