Yes, my mind boggled at that price, too. I'm a bit sceptical about 'period poverty' (yes I know that some people are really hard up) because my mum used to talk about the way she and others managed. She was born in Govan in 1913, 5 brothers and her dad died when she was 10 - so not a lot of cash around. People cut bits of cloth up and made them into pads, which they laundered for re-use. OK, definitely not ideal, but it meant that they got on with school, life etc..
I can't honestly see spending more than a couple of pounds a month on pads etc.. I never did.