Well, firstly, you can't compare dollars vs. dollars for something complete with something you build yourself.
You need to include cost and labor when making the comparison. Where a rough estimate of labor would be the hourly rate of what your regular job is now.
So if the materials for your pad cost $100.00, and it took 10 hours to design and build, and you make $50.00 per hour, than the true cost of your homebuilt pad would be $600.00!!!!
In otherwords, you can pocket that $100.00, work 6 hours overtime, and buy that $325.00 mount for much less than your homebuilt mount.
But building and learning is the secondary benefit...that PVC pad design came from the 16-pound melon sitting on top of my shoulders.
Now then, the materials (indcluding rail) cost me $75, the design cost me a an hours worth of sleep whilest I jotted it down on paper before it left my head. From start to finish, it took four hours (I took my time)
So lets plug your numbers in...since we are not including a labor of love here, we will use the time we value as precious...although I do not value my labor at $50 an hour, I will be as realistic as I can: 1(hour of sleep) + 4(hours of labor) + 1(hour to shop for materials) = 6-hours. X(times) my actual work labor rate of a whopping $16.10 an hour = $96.60
Still plugging here: $75(in materials) + $96.60(in labor) = $171.60
...for a grand savings of: $325 - $171.60 = $153.40
I am not saying that Ronspads.com are not worth the price, what I am saying is I can build mine cheaper. The above numbers mean squat (yours and mine). I designed and built one of the best pads I will ever own. You can't put a price on that. I know of at least two confirmed fliers who have built and flown from this design. At least one of these fliers has since burnt his to the ground...litterally!! Regardless, I have done all of the hard work, so strike a hours labor off of this design (no sense re-inventing the wheel) and you have yourself one kick-fanny pad, for less than a bill ($100) in parts (price your labor however you see fit).
OT here: my pad has also been submitted to:
https://www.pvcplans.com/pvc-pipe.htm
Lots of cool stuff at that website.
Final note: I will never let my ingenuity get in my way because someone else has done something similar or maybe even cheaper...thats why I scratch build everything now...it so much more rewarding.
Johnnie