Those prices are pretty much what I would expect for an FA Cup Quarter Final against another Premier League team.
As for actual pricing, I remember (when I could get tickets through my Citycard) in 2010 it went up 100% ,from £20 to £40 (for similair seats) from the Arsenal QF in the League cup to the SF v the rags. That one was perhaps a little different as it was our first semi final for years and was against 'them.'
For the Burton semi final in 2019(again League Cup) I think I paid a lot less, about £27 on East Level 2, which worked out at about £3 a goal that night.
Are they too much this year? probably, and as many have said a lot will be snapped up by neutrals/tourists. Are the club really bothered, probably not because they will say we are watching a very high quality product (which we are).
A lot of season ticket holders/Cityzens( who obviously should get the option of tickets first for any 'big' games)may well not go to this match. However it doesn't seem to go to open sale anymore to fans with a 'purchase history' ie: have attended a number of games In previous years, or has that concept simply been lost in the current 'business model' and the club don't care who gets them? This is the thing that bugs me as much as the extortionate price of actually attending games in this country, which I have come to expect (rightly or wrongly?)