This USB-C PD charger from UGREEN isn’t the smallest on the market, and it’s sure not the most powerful, but at $7 today (after clipping the 20% coupon and adding promo code KINJA30OFF at checkout), it’s one of the cheapest we’ve ever seen.
At 18W, it’s not going to be ideal for charging laptops (though it and while they’re asleep, albeit slowly), but pair it with a USB-C to Lightning cable (like the one on sale here), and you can charge an iPhone from 0% to 50% in just 30 minutes.