How much will you be charged for that hotel stay? The answer, of course, should be obvious: You’ll pay the published rate, plus government-imposed taxes and fees. Whatever that total turns out to be is your price.

But not always. At hotels that charge resort fees, you won’t just pay the published rate plus taxes and fees; you’ll pay the published rate plus taxes and fees, plus a mandatory resort fee, that can be as much as $100 and significantly increase the bottom-line price. (In a January Las Vegas stay, the resort fee at the Luxor hotel boosted my hotel bill by 34 percent.)

While the resort fee is mandatory—no one is exempt, whether they use the “resort” amenities or not—it is not simply folded into the published rate, as common sense and basic business ethics would suggest it should be. In order to allow the hotels to quote a lower base price, it’s broken out and treated as a separate surcharge, which is often only disclosed a few steps into the booking process.

Imagine buying a car for an agreed-on price, and being advised, just prior to signing the sales contract, that the steering wheel wasn’t included and must be purchased at additional cost.

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In a flimsy attempt to defuse consumer and regulator anger over the practice, the American Hotel and Lodging Association pointed out that as recently as 2014, “only” 7 percent of 53,000 hotels were charging resort fees. But that’s almost 4,000 hotels engaging in behavior that was deemed misleading by 80 percent of those responding to a recent survey by Travelers United.

Charging resort fees is unethical in itself. And the way they’re charged is misleading and deceptive. The fees should be banned outright.

U.S. Senator Claire McCaskill agrees, up to a point. McCaskill has introduced a bill that would force hotels to include all resort fees in their advertised prices, and give the Federal Trade Commission and state attorneys general the authority to take legal action against hotels that fail to comply.

The bill doesn’t ban resort fees per se. But requiring hotels to disclose them up front would make them irrelevant from a pricing-strategy standpoint, and the hotels would likely abandon the practice.

In any case, it would be an important step in the direction of transparent pricing. Consumers deserve no less.

Reader Reality Check

Resort fees: Yea or nay?

After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim Winship is Editor-at-Large.