'Do you buy Online if so how much.?'
Everything that I possibly can - to get the best reductions possible. I have even found that my favourite ground coffee is cheapest at Amazon with free delivery!
To obtain even better value I use a free credit card that pays 1% cash back on everything and I pay the full bill every month. Everything that I buy that exceeds £1 goes on the card, which amounts to a considerable cash back payment annually.
I accept that this affects the high street outlets but there are still very many people who will not shop on line and also pay cash for everything. These people are subsidising my life style and, for that, I thank them.