My wife an I have an agreement, no bikes sit on the floor (other than hers, which have kickstands). That rule drives my decisions.

I have hanging capabilities for 12, and I'm streamlining back to put my entire collection onto one 7-bike rack that is about 10' long.
It came from WalMart's clearance section, one of those wall hanging systems, and it works well.

For now, I have a 4-bike wall area in a nook that is reserved for cehowardGS's projects. He's my build motivator. When his are done, it will be a lofted mower garage, Christmas stuff on the second level (14' garage ceiling).

Upthewazoo hit upon what many of us have thought about, storage racks NOT made for bikes, and therefore 1/2 to 1/3 the price of those that are.
That rack he bought is nearly identical to a bike-specific one that often runs about $40-$50 at bike shops.