AmazonBasics Carry-On Travel Backpack | $36 | Amazon
Sitting somewhere between a wheeled suitcase and a big-ass duffel bag, AmazonBasics’ carry-on travel backpack likely holds a bit more gear than its 21.5" length might indicate, since it doesn’t have to devote any interior space to wheels. You can also carry it in a whole bunch of different ways, as its backpack straps, duffel-style shoulder strap, sternum strap, and waist belt are all easily removable. If it seems like something you’d want for your next trip, it’s only $36 today, which is less than a single checked baggage fee.