A load of hot air
In 2017, some particularly eager Adele fans listed sealed plastic bags full of air collected at her concert on eBay. The seller claimed their listing reached a gasp-worthy £1,500 before eBay took it down. For that much money, you could hire your own personal bouncy castle for 10 days, and arguably have a lot more fun with a bag of air. And, er, air’s free guys, even if it has been breathed by a musical goddess.