Bully for you. I can't imagine neither knowing nor caring how much anything costs; are you sure you're not an MP?
I have a fair idea how much fuel costs at the stations in my area, and I buy it when I need it at the station usually cheapest for whatever I want, but I don't drive around looking for a better deal. The only exceptions were during the fuel shortage, when I bought both diesel and petrol at the local (Beaconsfield) motorway services, two miles away, because that was the only place I could find them. The price was high, but it was pay that or run out. The cost was irrelevant; I needed it, and I could afford it. If it had been twice the price, I'd still have bought it; I needed it, and I could afford it.
I too do the weekly shop, and again, I have a fair idea which supermarkets are better on price for the things I need. If something is only available at Waitrose (Two for the price of three...), then I'll buy it there; I need/want it, and I can afford it.
There's quite a considerable difference between not knowing the exact price of anything, and not caring whether or not you're paying more than you need to, though. I've got a few spare pints of milk, as it happens; three quid each to you, guv'nor - bargain at that price, cutting me own throat, can't say fairer than that...
Time poor, cash rich, eh? As I said, bully for you.