cfblack

I like the idea. LCC's aren't anywhere close to spam-lines. LCC's still have to charge a reasonable amount based on the standard costs of operating aircraft and landing fees, etc, so they can't exactly undercut the prices too much because past a certain point they lose money and go bankrupt. 

As it is in the real world, LCC's go tits up all the time because their business models don't work as well anymore. Stuff is too costly. You could probably simply issue a cap based on the first cost established on a given route and only allow a certain percentage to be charged below the starting cost. Make it more biased towards IFE and IFS as well as marketing. 

I imagine with a few little tweaks you could prevent spammers from ruining the game and ensure people have to actually try and be a legit airline. Those who don't won't last. Than you don't have to ban anyone, you simply make it impossible to thrive.