Hamish, you are absolutely right IMO about the pricing issue. All the factors you mention are true but there are some others too. Sometimes an accident in the lab such as contamination can cause loss all or part of multiplication stock. It takes a while for the stock levels to be built up again and that causes a hole in supply a year or two down the line. Low supply + High Demand = High Prices.
Taking the specific example of N. hamata, there was yet another factor: The owner of the cultures we were using under license, terminated our right to produce it any more. We had to return his cultures and burn nursery stock on video (really, really, horrible thing to have to do!). Therefore, we then had to travel to another country to negotiate and purchase cultures from another producer. Apart from being expensive, this caused a shortage in the nurseries that we are just recovering from now. Soon however, the supply will loosen up and prices will fall but not dramatically as in the case of N. campanulata. I really don't know what happened there and feel sorry for people that paid US$180 for it!
Nearly everything we have, we grow out to ensure it's pure and correctly identified before offering it for sale. Sometimes mistakes are made but they are quite rare these days. Exceptions to this are (for example) N. platychila, where it became known we had it and demand was so high that we yielded to pressure to release plants at very small size. However, it's clear that they are seed grown and the buyer takes his or her chances that it may be a hybrid. They're pretty much sold out now and the next batch will be coming out of the lab. We keep 24 clones in the lab and will grow them to a sufficient size that we can be sure of their purity before selling them. We did the same thing with the first N. jacquelineae to be released, sold them seed grown and very small. A proportion of them turned out to be hybrids with N. izumiae - fortunately a highly attractive hybrid!
Another souce of error was that some of the TC clones we had under license from the third party mentioned above turned out not to be what he said they were. In the early days we trusted his identification and sold plants at small size that were incorrectly labeled. An example is N. burkei which turned out to be N. ventricosa and a number of others. Also, we have had sterile material donated to us from botanic gardens that turned out to be wrongly labelled e.g. N. faizaliana (actually the parent plants in the Botanic Garden concerned had been incorrectly identified). These mistakes can and occasionally are, made in all good faith.
It's very easy to make labelling errors both in the lab and in the nursery which is a problem we've been tackling for years. At one time I used to personally check each plant before it came out of the pot but these days there are just too many being shipped for me to do that and not all our staff can recognise a labelling error, so we have to be very careful to ensure each plant is correctly labelled from the lab, to the day it's shipped. We've achieved this with a system of stock control and multiple checks that seems to work well now.
Finally, at the risk of turning this posting into a book
there is sometimes academic debate over the veracity of a species. For years, we sold what we (and everyone else) believed to be N. thorelii. Now, thanks to recent field and herbarium reseach by Marcello Catalani, it turns out that it's probably N. anamensis and true N. thorelii may be extremely rare in cultivation.
Sounds like I'm making excuses for BE doesn't it? Not really, I'm actually proud of our track record and we are enthusiasts, not just businessmen but I wanted to explain that consistently correct identification and labelling is a complex issue, especially when nursery buldings and lab are hundreds of Km apart!
Deliberately marketing a plant you know to be incorrectly labelled is another matter entirely, raising all sorts of ethical and legal concerns as you mention Hamish. I'd better not comment further on that...