Whatever I wear, I always buy clothes I feel comfortable in but whether smart, every-day or slobbing, I always buy something that is comfortable and looks nice and suits me. For me being comfortable in my clothes is physical and mental.Even my gardening fleece is in a colour that suits me and goes well with elderly jeans!
If you are spending your hard-earned money (and pensions are hard-earned money deferred) why waste it on something unflattering, even from a charity shop. I bought two beautiful skirts and a fake fur coat in a local charity shop last year and I feel really good in all three.