My car is an ebay special. (everything on ebay unless stated).
Audi Pepperpots: £40 - £20 from the sale of the balloon tyres. (Two replacement caps: one £10 and one £14).
Front Anniversary Smoked Fogs/Middle Blanks/Indicators: £20.
VR6 Splitter: £36. Volksmine (yes I know the bay is cheaper - these ones come through TPS and don't seem to shatter so easy, £18 a side - still broken 2 and had the passenger side stolen

).
Vento front end: £80. +£150 paint (grille, bonnet, bumper, wings flicked in and lacquer peel on tailgate fixed).
Vento early front grille: £15
Vento Mattig eyebrow (not yet fitted): £10
Hella Magic Colours All Black Rear lights: £12. Yes.
£12.
Magnex Stainless Steel Exhaust: £140 (Private Sale)
Front and rear Cross drilled and grooved discs, fast road pads, rear bearings: £100 (Edition 38)
Storm Single Wiper kit: £6.
Smoked MK4 side repeaters: £4 (GSF)
Black Passat B3 Grab handles: £5 (breakers)
Black Sunvisors: £22
Audi A2 Gearknob (new, boxed): £15.
Fischer C Box: £9.99. (Bought one for £35 from Edition originally, sold on for same).
Vento Car Bra: £30 from the bra factory (discount for being the first person he ever sold a bra to when I bought the first mk3 Golf bra he sold

)
Total: £678.99. £250 of which has been on the vento front and paint. Not bad going I reckon.

There have been other mods I have bought and then sold on, never made a loss on anything.
Keeping the car running and legal is another matter, with tyres and service bits and general repair stuff, I have probably spent over £2k in 3 years. But then it has done 70k miles.