I don't.

Good. That means you won't be disappointed when you practically starve to death owning an airline. ;D
If you're really serious about this, I'd advise you to not think big just yet (I assume you're shopping for Boeing airliners?)... think small first; think charter operation or something like that, with smaller aircraft.
Any bargain jet airliner you find will wind up costing you much, much more in the long run than if you paid more initially for a better one.
Also, bear in mind that even the big boys are scrambling for revenue- it's a very, very, very,
very competitive market right now, and probably will remain that way for some time.
On the upside of that, there are many furloughed pilots out there- easy pickings for your roster, as long as they're willing to wait a few years to get paid.

If I were contemplating the joys and agonies of running an aviation-related business, I'd sooner set up a timeshare or fractional-ownership thing with one or two turboprops or light jet or something... that's an expanding corner of the market where there's still room for little guys to gain a foothold.
And no, I can't lend you any money- but I'll keep an eye out for your IPO and buy a coupla shares.
