What would you do for a lower fare?

Would you sacrifice your carry-on bag? Forgo seat selection? Agree to board last? Go on the Whole30 diet to lighten the load and help reduce fuel costs?

Airlines are betting that passengers will agree to all but one of those capitulations to save some money.

Until recently, only the scrappy outliers Spirit and Frontier offered the plucked-chicken pricing model. Passengers pay a cheap fare for a space on the plane but can tack on such feathers as carry-on bags and preferred seating for additional fees. Last week, two of the major airlines joined the stripped-down flock.

COUNT THE NOPES

After several months of anticipation, American and United have introduced the Basic Economy category in select markets. United is initially offering the main cabin fare between Minneapolis and these seven airports: Chicago O’Hare, Denver, Houston, Los Angeles, Newark, San Francisco and Washington Dulles, for travel starting April 18. On American, the option appears on a mix-and-match of routes featuring Charlotte, Orlando, Dallas-Fort Worth, Philadelphia, Miami, Tampa, New Orleans, Fort Lauderdale and Baltimore-Washington International, for travel starting March 1. (About two years ago, Delta rolled out a similar fare, but without the second-bag surrender.)

To nab the lowest price, you will have to divest yourself of the typical comforts. (Some exemptions apply to members of frequent-flier programs who have achieved a certain status level.) Among the nopes: No seat assignment until after check-in or at the gate; no same-day ticket changes; no refunds after the 24-hour cancellation period; no upgrades; and no bags that require storage overhead. Also, no need to sprint to the gate: You are boarding with the last group. However, once on board, Basic Economists receive the usual in-flight treatment of free drinks, snacks, entertainment and WiFi. The personal item at your feet will remind you of your purchasing decision.

The new fare is a cause for celebration among ascetic travelers but may baffle more entitled types who want to have their cheap cake and eat it, too. To help make an informed decision, we planned an imaginary trip to compare the fare differences. Interestingly, both airlines have added another step in the booking process. After plugging in the destinations and dates and choosing Basic Economy, a page pops up detailing the restrictions and, in American’s case, asks, “Are you sure?” Perhaps it could sense the uncertainty in our key strokes.

BAG FEES PACK A WALLOP

For United, we faux-booked an early May flight from Dulles to Minneapolis. The lowest Basic Economy fare was $244 round trip. By comparison, the lowest Economy fare was $284. On Spirit, the lowest fare from BWI to the Twin Cities is $158. Spirit’s carry-on fee ranges from $35 to $100, depending on the time of payment. Arrive with a second bag on United and the airline will charge you a $25 checked bag fee plus a $25 handling charge.

For American, we pretend-reserved a May flight from Philadelphia to Fort Lauderdale. Basic Economy started at $154; the Main Cabin was from $194. Spirit charges from $106, plus the aforementioned baggage fee. United penalizes second bags with a $50 fee.

So, Class, what did we learn? Spirit has the lowest fares, but that’s no surprise to travelers accustomed to repeat sock wearings. But for passengers who prefer the more robust service of the legacy airlines, Basic Economy might not be worth it if you have to check more bags or if the suffering outweighs the nominal savings. However, if you can pocket a significant amount of cash, you can travel like Hobo Snoopy but enjoy the destination like Richie Rich.