It is a running joke with my friends; how many helmets will he buy this year...
I have 3 bikes, no excuse btw,

and own 12 helmets currently. 2 enduro, one modular / flip-top and the rest regular full face helmets. I've been riding 22 yrs so some are a bit old but TBH I have bought at least 1-2 per yr over the last few yrs because of:
- greater variety of helmets
- lower prices
- ebay - even Arai's and Shoei's are more reasonable
- Motorcycle-USA et al, and the internet equals less cost
- more disposable income
- I'm a SINK and a motorcycle-nut = bad combination
I keep at least 2-10 helmet on my ebay want list and temper my purchases for the summer - trackdays - but lose control in the winter.
I just bought the S1000RR and likely to pick up the Panigale or MVF4RR... I already have the Ago replica helmet on my next purchase list.
The holy grail... Dunlop Arai... saw one on Ebay ... well over $1000

Yeah I'm not that bad... yet.