Actually, £150 is about $270 right now so it's close to even money - but they gave me a bit of a break on the mark-up. No extra for fitting - maybe that was already built in to the price. I was happy to get them to do that - those battery's are heavy!
When I mention the price some people say "What...?", while others, such as a bloke in an auto accessory shop today, say "Hmmm, good price!". The latter knew it was S/S of course.
The equivalent here can be obtained for AU$133 or £75, guess we go through far more batteries here due to the weather (possibly) and popularity(by regulation) of SS cars ? making them cheaper.
https://www.batterymegastore.co.uk/car-batteries/agm-car-batteries/hankook-se56010.html