Its hard to know really what goes through the mind of your average Ryanair passenger, but I would imagine most of them would be quite happy buying a ticket for a flight that was advertised for €49.99 to some little airstrip near some former industrial town or wherever, actually cost them €49.99 as opposed to a flight that was advertised for 99c but ended up costing them €49.99.....
There'd be no complaints about misleading advertising or hidden charges and it wouldn't even cost Ryanair any extra.......
Lets not get carried away here - a flight advertised at 99c can only cost a max. of €15.99 (€20.99 come October 1st) even if you pay with Visa, Mastercard, etc. and check in a bag.