Yes, $25 is very reasonable, considering! And yes, since Gossard is saying that different fans from a conversion can have different ploidy, it kind of leaves you out there wondering. So I suppose that if someone has been growing a clump with established ploidy, it is a good bet.
Conversion is very interesting, but the detailed accounts I have read of how this is done, I find hair-raising. I tease my husband about the Hazmat suit I am getting him for Christmas..
Beyond ploidy, I understand that some cultivars are simply rust-resistant. You have to wonder why your dls were listed as rust resistant, when they are not! Perhaps rust is evolving into a more persistent type....Since I am in Vermont, I admit I have not paid much attention to this factor.