Good call Nora.... £150 just for a Briggo deflector is ridiculous.
Bad changes a few years ago was when they were trying to slow things down and kept changing the type of silencer and the carb sizes.
When I first bought a bike I could use a 38mm carb, then the rule was changed to 36mm and then 34mm. Carbs are not cheap.
Another thing was tyres. We had Pirelli tyres and a few had Dunlop.
I used to buy my Dunlop from Bob Humphreys for a couple of quid after he had done a couple of rides on each side, then Briggo (who else?!) started getting the Carlisle tyres from America that were meant to be the muts nuts, but they were so expensive. I think someone in the Control Board must have got jealous as we then had the rule where everyone had to use Barum