I really believe Scadden is the Mercedes of the inflatable tube / pontoon manufacturers and by comparison they have Mercedes prices, it's pretty hard to get into a new boat for under a grand. Outcast get the runner up prize in my opinion with good boats for under $500 with their Trinity weighing in at 7 lbs. The Fish Cast Deluxe is under 14 lbs. for just the tube. I have a LCS 4 which is around 20 lbs. You are going to need fins and a inflation pump also.
It's easier to fool people than to convince them that they have been fooled. Mark Twain