Which airlines sell 'basic' first and business-class fares? What to know before you book

We're talking about the growing number of U.S. carriers that now offer "unbundled" tickets even for passengers sitting at the front of the plane.Booking a United Airlines Polaris suite? The lowest price you see may be a "basic" business fare — and if you buy it, you can't enter the airline's swanky Polaris Lounge.Delta Air Lines has a similar policy for its lowest business fares: No Delta One Lounge access is included.SEAN CUDAHY/THE POINTS GUYOn both airlines, passengers booking those skinny premium fares can't pick their seat or make itinerary changes.JetBlue plans to roll out similarly stripped-down fares when it launches its new domestic first-class cabin later this year.More choice or higher prices?Unbundled fares are nothing new.U.S. airlines have been selling basic economy fares widely for close to a decade.Historically, these tickets have offered customers a trade-off: Book the lowest price point but stomach some restrictions.Reward your inbox with the TPG Daily newsletterJoin over 700,000 readers for breaking news, in-depth guides and exclusive deals from TPG’s expertsBy signing up, you will receive newsletters and promotional content and agree to our Terms of Use and ackn...