It will be up to the individual generosity of forum members as to how long this will go. If I have to pay all the shipping, it isn't going to go far. Donations will keep the ball rolling. It is not up to me to say "How much" per plant, and I'm not going to. I like to think of it like this, Your plants are free, and the money you send will "purchase" the plants for the next guy, who may not be as flush as you. Generosity has to be a personal thing, it can't be required. I believe that I can count on the generosity of friends to make this work in a way far better than if tried to sell the material, and use the proceeds to continue my efforts. Time will tell if this is true or not.
Sorry to disappoint regarding the petiolaris, but I lost most of my plants in the winter freeze that decimated my collection. Although I have a great quantity of plants to offer, these plants will not be among them. Perhaps next season if I can manage to get more of them and have a little success in reproducing them this will be possible, but right now I am looking myself.