Hive the shipping charges were in the open, I really think its a bad move dinging his dsr's provided he gets the package fast. If you know the charge buy it or pass.
Unless you think $50 is intrinsically fair for shipping, then there is no reason NOT to ding the DSRs. It doesn't matter how we feel about the OP and if he was making a sound decision; DSRs are a rating system, and $50 S/H for something that should be about half that should rate poorly. If the seller doesn't like it, he should charge what it actually costs.
If the OP were complaining, then we flame him for it. But overpriced shipping is overpriced shipping; and we all agree that it's overpriced.