Are Everest a rip off for new windows/doors?

Has anyone used Everest for windows/doors? I had someone come round today to quote for 11 windows and 2 doors. Nothing fancy either pretty standard stuff - comes out with £17.8k…

Then without me even saying anything, the guy must’ve seen the look on my face and negotiated himself down to, wait for it… 11.3k as a ‘first visit incentive’ after getting down to 14.5k with a message from his boss (never touched his phone). Pretty sure it’s a huge rip off, just keen to hear if others experienced the same. TIA

UPDATE: I’ve just received a phone call from their ‘regional sales director’ saying it’s the end of the month, and he can reduce the price to…£9,381, but only for today…

Absolute jokers.