It’s not a 40% discount. It’s 40% off of MSRP.
For example, a plain G-10 PM2 is $265 MSRP.
OpFocus price: $159
Street (MAP) price: $198.75
That’s about a 20% discount.
Some legal jurisdictions think so, but IME handle size matters a lot more. I can’t think of any task I use a 4” folder for that a 2.5” folder won’t do.