I've bought a number of things from solarseller.com over the years. I needed some battery cable lug ends again. 14 of them, 2/0 size. Locally they varied from 2.79 to 3.19 each. If I'd only needed a couple I would have bought them at the local hardware store. But when solarseller.com has solid copper ones that are also tinned for $1.05 each in quantities over 10 it works out cheaper to pay the shipping.
After the order was placed and I received an email stating it was shipped I got a further email from them. They said that the actual shipping cost (USPS Priority mail) was 2.95 less than the amount the shopping cart charged. So they refunded the 2.95 to my CC. Way cool. They could have easily kept it.