First of all the correct number of bikes is n + 1.
For example I currently own 4 bikes and have a 5th on order. I will sell one of the other bikes when the 5th comes in but begrudgingly. My house spouse has 7 bikes. We don't have any tandems. So that's 11 bikes between the 2 of us and I could justify more for sure. You don't need to worry about hoarding, yet.
Living life like there's no tomorrow.
http://gorgebikefitter.com/
2007 Look Dura Ace
2010 Custom Tonic cross with discs, SRAM
2012 Moots YBB 2 x 10 Shimano XTR
2014 Soma B-Side SS