I used to think Jacksons were pricey till I had a need to buy one or two items for my caravan. I purchased then with a Discount card from GoOutdoors at Coventry, goodness I wished I'd shopped at Jacksons. I know that some items they sell are on or near RRP but they do sell a lot of things you cant buy elsewhere. They also sell some second hand items, which at least you can examine before you buy.
Postie told me this evening of a heater thats a good bit cheaper elsewhere as compared with Jacksons, but I guess its horses for courses. I needed a clip for my fridge vent, and a cover for a water pump hook up point, jacksons were a lot cheaper. I do like looking around the place too, so many nooks and crannies with a bargain or two here and there.