According to a report from Priceonomics, the markup can be as high as 300 percent for simple snacks like potato chips or pretzels.

As if a $4 Coke wasn’t pricey enough. Check out the average markup on some of the most popular mini-bar snacks and drinks.

A 2012 survey conducted by lastminute.com – the online travel booking site – concluded that among the 500 hoteliers they polled, 84 percent said that guests attempted to cover up items they stole out of the mini-bar

Today, about 85 percent of hotel mini-bars have some type of electronic scale or sensor to detect when an item has been tampered with, reports Priceonomics.

But other chains, such as Hyatt and Hilton hotels, have already done away with their mini-bars all together, citing low profits and changing consumer preference. So, you better remember to buy that bottle of water before check in – or you can wind up high and dry.