My office is in Munich, and 5 mins away from TT. I buy most of my stuff there (Kahedo seat, £229 here, £171 in Munich).
Actually, legally, they may be on sticky ground as we are in the common market, they can't refuse to sell you the stuff. This is the issue the the car manufacturer's had when everyone was flocking to the continent and saving themselves a few grand by doing a personal import. The big manufacturer's tried to stop it, got taken to court, and lost.
That's the point of being in the EU! At least, apart from robbing us or sovereignty, having thousands of laws and regulation imposed on us by unelected beaurocrats and knocking a few% off our GDP, that is.
If you feel strongly, you could take it further. Or just get a job where you go to germany a lot