Was looking at a cheap high power usb c adapter for my new laptop and the generic chargers were c. 18 quid on Amazon so thought I would check cex. Found they do genuine apple for the same money, didn't fancy risking my new gaming laptop with a dodgy charger! They seem to be about 30-40 quid on eBay if you can navigate the fake ones on there.
There is also a 140w version for a £27 delivered here if your laptop supports it:
uk.webuy.com/pro…42A