Core comparison
In short: the cheapest way to Luton Airport from London is usually a coach from around £11, such as the Green Line 757 or National Express from Victoria. The train option is a Thameslink service from St Pancras, Farringdon or City Thameslink to Luton Airport Parkway, plus the £4.90 DART people-mover to the terminal, which together come to roughly £16 to £18 on a through-ticket. A fixed-fare transfer from about £35 can be the cheapest per head for a group.