Yeah, I seen those. He is the only one selling them for $245. I provide a link to his website in my links section. I believe there is room for more than a few people offering the same product.
Someone said on another website, that they paid $400 for a set from another dealer and they were glad to do it because of the 5 year warranty.
Another website has shunt coils that are wound on nylon bobbins. They don't have paper insulation either.
The ones in the link above look like they are wound on metal bobbins and have paper insulation. That's the way mine came from the factory and I'm sure paper insulation and metal bobbins are fine.
My shunt coils are bad. A post mortem seems to indicate they went bad near the bobbin, close to the corner. It looks as if moisture gathered in the lower corners and cause some sort of reaction that caused a winding to winding short. I don't know if this is because the paper insulator held on to moisture and allowed it to collect there or something else happened. There wasn't a winding to bobbin short in my coils though.
I do know that there was not enough varnish on my coils. The only place I found varnish was on the outside of the wraps. There are 4 sides to the coil of wire and only one has the varnish. My coils failed where there was no varnish other than the coating that came on the wire that makes it magnet wire.
I also realise that selling a product involves more than just making a product and selling it for money. A business has a reputation that comes with it. Products have to do what they are marketed and sold to do. Customer service, shipping, communication, reliability, all go with serving customers. Nowdays technical support is starting to be an important part of business. A person can offer a product but the superior companies will send a tech sheet with inspection results. Are there many companies that offer installation videos to go with the product or troubleshooting videos to show how to test something to make sure its bad before you drop lots of cash on something that might not be bad?
For now I'm just looking to see if there is a large enough market (and competition) to see if the initial investment in getting up and running is worth it.