I have been to the vegetable shop today and bought another sack of potatoes and my supplier indicated to me that they believed that pototoes were going to be a little scarcer this coming year as not so many farmers out their way are going to be planting them (Spalding area). Therefore if you have the land it might be worth growing a few of your own if you can. I am afraid I always buy a very big bag of spuds as you can always get a good meal out of them. The last lot that I got were Cara and were £5 - far cheaper than the supermarket and far more meals out of a bag. During all the snow recently the farmers had closed the potato sheds, and were having difficulty lifting other veg as well.
Cauliflowers have also been £1.50 each - in fact they wouldn't buy them - the area in which I live is not very wealthy with a lot of people on benefits so at that price they didn't think they would get rid of any and so it would be false economy in stocking them, so Cauliflower has been missing off the menu for the past few weeks or so. Other half adores Cauliflower cheese.
So if you have the room grow some potatoes yourself. Wilkinsons have seed potatoes in stock at the moment and you never know having a go may well spur a life long interest in gardening and feeding the family.