Well if you want to look at it this way, a product for sale should be way cheaper than any one off product by far due to the fact of set up being done, jig tables, measurements cataloged, design completed.......blah blah.....
If i gave you a price on what it would cost me to build, it would seem as if i was trying to undermine SleeOffroad and that is just not my style.
On the subject of leverage the lighter 120 wall round tube is probably 5 x stronger than a square tube of the same gage thickness, "the dome effect". Get a 120 wall square tube and a 120 wall round, ********** each one with a hammer and the square will be the worse off, so you end up having to run a heavier gage and weight square tube to accomplish similar strength of the lighter round tube. So you say a slider that is 50 - 70lbs isn't going to put more stress on the frame than one that is 30 - 35lbs??????? On or off vehicle weight, this still would add more stress due to what it is attached too, frame plates or not.The lighter the product, the more of an extension of frame it becomes instead of a lever on the frame. This is the point i was trying to make before and this comes from experience wheeling, fabricating, and testing. I'm not making this up to hear myself talk to myself.
This post is not an attempt to under mine Slee's costs of doing business or his product design. This is just to answer the question.