IMHO all of the marine BBQs are grossly overpriced. I have had 3 of the Magna round units with the cable attached lid. They were hard to light, blew out easily, and difficult to clean.
My current BBQ is a Kuuma. It is rectangular and will fit two 1.75# lobsters. It has a robust cooking grate (compared to the Magna), easier to clean, doesn't blow out unless the gas is very low, and has a hinged lid enabling you to have both hands free to manipulate the food. It is still very expensive compared to a non-marine stainless steel home unit, but I think it is a much better value than the Magna. For instance, given the price I think it should have a push-button ignition, but it doesn't. I would recommend that you check out all of the available BBQs. Don't neglect looking at camping units- you may find them to be better for the money.