I agree with shipwreck66. After all was said and done - finding the product, buying the rail fittings etc it wasn't worth the time and effort I put into building my own - from a cost standpoint. My wife loved the seat. If a guest took her seat she'd wait untill they gave it up and then she'd grab it.
I'm going for the hat trick. I hate buying when I can fabricate something and save some $$$. But I priced out the starboard, the fittings, the tubing and the all-important cup holders, I was only saving about $20.
It is the most used add-on I made to my boat - wife and kids fight over them. I never get a chance to use them but I hear they're comfortable.