As per The Rules posted by Kirikou:
"The minimum number of bikes to own is 3. The correct number is (n + 1) where n = the number of bikes you own now OR (s - 1) where s = the number of bikes that will cause your partner to leave you."
Yes to the minimum of 3 (I can't believe the look people I get when I mention the minimum of 3).
There should also be some kind of extra variable based on time working in a bike shop (xN) because of pro deals.
How many boxes of bike tools per bike?