I have a Schuberth C3 with SRC bluetooth kit fitted.
Bought less than a year ago and used just twice - one short run, it was fine - one long run, and my head was starting to ache, so not quite a perfect fit. If anyone's interested, PM me.
C3 (helmet) metallic silver, size 60/61, cost me (from Just Helmets) £446.49 (now selling £469.99 on their site)
SRC (bluetooth), size XXS-L, cost me (from Just Helmets) £284.99 (now selling for £309.99 on their site)
I'll accept £400 for the pair.