I am guilty of this times a million. The only way I can remove myself from the +1 mentality is to totally stop looking at bikes online. I swear every single time I say I'm done, something else pops up for an outrageous deal. For instance, just today I saw a Fuji Roubaix that's just a few years old for $200. This bike has 10s 105 with nice wheels. It's taking all of my will power to not buy that bike and swap all the bits over to a cool old frame.
The problem as I see it is I don't have a spouse to keep me in check. I don't have anyone in my life who gets upset with me if I go spend a few hundred bucks on a bike. And in the end, I spend far less than the bikes are worth, so it's easy for me to justify. But perhaps February will be a good time to thin things out.