The original poster is in the UK apparently, so I think it's more like £99 inc. VAT.$129:
If you have a 2012 model it should also still be under warranty.
My battery health hovers around 80%
It has fallen to 78% before showing the service battery message.
I didn't manage to get to a apple store and the message and sub 80% hadn't returned
I have a 2011 MBA - is the 80% 1000 cycles valid for my laptop which is out of warranty or would I still need to pay for a replacement battery if it falls below 80% again on my 170 cycles?