If you are stocking up and tend to buy same household products you should start looking for special offers like. "buy 1 get 1 free" at each shop trip.
BTW It's more likely, that you'll find refill with dispenser cheaper or discounted rather than refill. Same with printers and ink cartridges.
I always follow my shoping list, but if I see e.g. domestos discounted, I buy few of them although I don't need them badly. I will nedd them sooner or later, but special offer will end till that time.
E.g. last Saturday I noticed in Tesco Duck fresh discs (dispenser + 1 refill) for €3.99 - buy 1 get 1 free. Box with 2 refills is €6.99, which means that buying 2 for €3.99, I pay for one and save €3 compare to box with refills. I bought 6 of them and saved €9:D
