No doubt the tractor seat system from Northern Tool or other implement retailer is going to be cheaper..and if thats what you are looking for is the "cheapest" method to get some suspension then the Smoothmoves or GlydeRyde systems are not for you. However, if you are looking for a seat system that has proven itself in extreme marine conditions with thousands of marine customers (between the two companies) and is going to be supported and designed to be easily installed in your boat using the same hole patterns and OEM standards that boat manufacturer's use then the Smoothmoves or GlydeRyde systems should be considered. They are both similar in design and function but differ when it comes to price, the Smoothmoves will put you out about $250-$300/side while the GlydeRyde system will set you back about $400/side. One upside to the GlydeRyde system is that they do make a stainless version and it may be an even better option for you guys that spend a lot of time in the salt..I think these run somewhere in the $500-$550 range per side.