I need a new microwave - the old one is rusting out - so went on line to find something I can afford that looks to be reasonable quality and able to fit into the restricted height under my kitchen cupboards, which are too low for a lot of models. For various reasons I ended up with a Cookworks model sold by Argos, but had a brainwave and checked on line to see if it was available from their ebay outlet. It is, at about £4 less if collected from one of their stores.
In other words I save about 8% on the price simply by ordering it the night before I collect it and via ebay.
I'm not sure what this says about Argos's pricing, but it's interesting. And they do this with a LOT of products, so it's always worth checking.