Time for a reality check here.
I'm an electromechanical field tech for a large fabrication company. In order to get in with the company and obtain my card I had to put up with 5 years of education in fabrication, layout, metallurgy and all forms of welding. I've been with this company for 13 years so I'd like to think I have a decent background on the subject.
The material there might have added up to $5 bucks in 1920. ¼" thick stainless does not come cheap. The replacement motor mount bolts, pinch bolt and spacer is not something you can run to ACE hardware and buy. Those are going to be custom made out of the correct tensile strength material. The connecting bar stock needs to be drilled dead center and then tapped.
All the bracket parts need to be cut to perfection, ends ground down, drilled out and then welded to perfection. Even with a jig made up that's going to take a lot of time.
Once you get that all worked out you now need to find a set of off the shelf good quality sliders to install on your brackets.
If I bought second Busa I would still order another set eventhough I have the means to make a duplicate copy of what I already have. My time is money and I don't work for WallyWorld wages. In other words it would be cheaper to buy them than bother with the hassle of making the brackets, outsourcing the engine mount bolts/spacers and buying good sliders (not the $20 shiny ebay bling crap that keeps your bike sliding down the highway).
If anybody pulls this off for $100 a set it will be out of the goodness of their heart due to the fact they'll be taking a huge loss once labor is added in.
Hope I didn't come off too harsh here, it's just that I think too many people are getting condition to the mass produced "made in China" slave labor junk out on the market these days.