As a self-confessed snob I used to avoid such places like the plague but having a baby and a serious dent in my bank balance means I had to change my ways. I am always scouting for a bargain now, I even go to Coventry market sometimes! ;-)
I think Poundland can be great for craft things and if you know the prices elsewhere you can get bargains on other things. Aldi and Lidl are definitely cheaper for many everyday items, I tend to spend too much on random 'stuff' in there though! Danger!