Actually, the Kordes roses were bred to be grown own root. They do not need the extra vigor provided by budding. That is one of the reasons they grow into monsters.
Since Ball Industries, owned by Star Roses, bought Newflora, including the US rights to Kordes roses, we will probably be finding Kordes roses available own root in more locations in the US.
Re: Heirlooms prices, the the new owner has paid to have his mother plants virus indexed to enhance his ability to sell clean roses. That's expensive.
He is also actually testing to see if the roses WILL grow well own root vs budded. Again, that's expensive.
Also, instead of selling rooted cuttings that are more like twigs, he is selling established plants. That means he has to strike a lot of cuttings, then grow them on for more than one season for them to reach the size of plant he has for sale with a solid root mass.
Yes, he is charging more money for the roses, but at least he is going through the process to provide a better product for the customer. I don't know if his prices are out of line. I don't know of any other own root nursery that sells virus indexed roses tested for own root viability at that size, so I can't compare prices.