I'll add a few random parts I picked up today, note these are retail prices from VW parts dept....
PLUG - 02M 301 115 B - £3.31 + VAT
(rubber plug, fits 6 speed diesel gearbox flywheel inspection hole)
BATTERY COVER - 1J0 915 435 B - £8.85 + VAT
(this is the large version for the diesel models, comes with the sticker fitted)
REFRIDGERANT S - 1J0 010 212 - £0.39 + VAT
(aircon sticker fitted to left of bonnet catch)
STICKER - 701 010 492 B - £2.67 + VAT
(fan/voltage/oil warning sticker fitted to left of bonnet catch - note the original sticker going by part no. 701 010 081 has been superceded by the version listed above)
SPEED NUT - N903 019 01 - £1.52 + VAT
(u-shape clip type things with M8 thread in, you need 2 of these to fit armrest)