I've been a big fan of all your introductions over the years and I try to get as many as I can when I see them offered from the usual sellers. The inverted cactus are my favorites. Till the voles decimated my crop this year I had +55 varieties of hollyhill.
All of us know how much work you and Margret put into your seedlings especially hand pollination. $40 - $50 is fair for a new intro and I personally have no problem with paying that. I also have collected a lot of the Parshalls intros. Seeing now which ones I need to replace