I went in to the MB dealer with a list of six online sources and their prices, $150 to $178 for an SL500 accelerator assembly. MB price was just over $200. I told them I prefer to support my local source, but it's hard when they are too high. He then offered 10% as the best he could do, about $180. I told him he was only $2 above the highest online, so I would give him the order. He appreciated that. Moral? It pays to go in prepared.