If you can figure out when 'vulture time' - i.e. when they mark down all the old stock - is at your supermarket then you can grab some really good bargains. Also quite a lot of supermarkets have started having super-cheap 'fruit and veg of the week' in an attempt to promote healthier eating - for example, CoOp usually has a selection for around 69p and Lidl for around 49p.
We've also had a lot of luck with the local covered market (Cardiff is blessed with a pretty big one) as the greengrocers there will often have a selection of '50p grab bags' of whatever they've bought too much of which also helps keep the piggies' diet fairly varied, as they'll get whatever is 'on special offer' that day - we've lucked out and had massive bunches of coriander, bags of pea pods, and vast quantities of peppers.
