How many spares do you have to add to an order to take the saving from £17 to £80/90 then?
If you save £17 on a £160 purchase surely you would need to spend BIG bucks to save the amounts you say. Plus, would you be buying all of those "spares" becasue they are needed or just to save money, since a decent LHS here should have them on the shelf waiting for you, so you dont have to keep them in YOUR pitbox.
Dont want my post(s) to sound like I am arguing because I am not, but If an average person brough a B4 FT out of one months pay packet then they would save just the £17, but to make these huge £80+ type savings on a regular basis would require a racer to be spending probably £600+ per month on their hobby (every month!! £6K per year, some probably do but not all!!)
At the end of the day as well, you dont get ripped off by customs, you just pay what your are meant and supposed to for an import.