I was gonna go ahead and order a humminbird 798ci si today from bbg marine, but on their site they have two listed, one is $750.05 and the other is $760.00. What is the difference in these two units if any, the descriptions are the same, the date they started carrying these is different and there is a cw33664 on one and 33664 on the other. I want to get it coming, but want to order the right one.