I once helped clean up after a festival in the UK—a relatively small venue that hosted around 10,000 people. It was incredible to see £450 tents, used for just three nights, simply abandoned. Among the most surprising finds were £300 Rab sleeping bags still in their original packaging (apparently the weather had been too warm to need them) and cash scattered across tent floors. Walking through the aftermath felt like browsing an outdoor gear store virtually anything you could want was there, barely used after just three days.
P.S. Really enjoyed Catch and Kill.