I don't think TNA will be hard to find in the future. Every "keeper" eventually comes up for sale. AMH was commanding near 10K prices during its manufacturing run because of its limited (150) number. But I had 3 second hand ones to choose from when I went looking for one last year. At the slow build pace, there will probably be some used TNA's available before current orders are filled. This is an interesting thread because I've contemplated the same question.