Alice we used to do that too! When Gardenweb was online and heavily attended we traded water lilies like crazy. I had a friend here (who has since given up all her plants and stopped gardening at all due to health reasons) who also had a large greenhouse. Her specialty was succulents, orchids and caudiciforms but we both had sizable water lily collections, I had about 40 different tropical lilies.
We had friends in the surrounding area in Newberry, Brooker, Micanopy, even as far away as Green Cove Springs. We would have big organized trades at each others houses. For ANY type of plant (except annuals). We would advertise the trades on Gardenweb Florida forum and people would come, and bring a covered dish and lawn chairs, the hostess would provide the paper plates cups and plastic cutlery. We traded plants, and ate, and had a great time.
No one does this anymore, but I still have a list of contacts from the old days who still do trade with people they know and trust not to stiff them. As with everything, there were bad apples in trading. But its really the way to go. I have obtained replacement plants for plants that I lost during my absence from the greenhouse that have just skyrocketed in price, I would not have been able to afford to buy them again.
Before my advancing age and several moves I had a sizable collection of plants and most of them came from trades or cuttings/divisions. When I had a large pond I would organize trades for water lilies. A good quality named hybrid lily could cost between $25 and $50 easily which I never understood because they multiply like weeds. I would tell newbies to only buy one good plant and, by trading, they could have a whole collection by the following summer. 
