I think cycads are expensive for two main reasons. Lack of propagation material at a cheap price (except Cycas revoluta) and the time to get these things to a decent size, ie many years. Palms are cheaper, but generally grow faster and propagation material is generally cheaper and easier to find than cycads. Are they making bigger margins on cycads than palms? Maybe in some cases, but I would think in the majority of cases no. I'd say the margins would be similar, or even less for some cycads. Unless someone is a collector and specifically after the rarer stuff, rare cycads would sit forever at the nursery if the proper margin was put on them. The average landscaper/home gardener wants the right look for the right price and they'd walk past an expensive rare cycad. So to sell the rarer stuff, the nursery would have to lower the price and reduce their margins. The challenge for nursery owners is to create repeat custom, and if possible create an enthusiast or collector of these rarer ones. This is done by friendly enthusiastic education of the client. As the client learns over time what the differences are, they can see the subtle differences and will want more. When I first started into palms, most palms looked very much alike, until I learned and could tell the difference. By then I was hooked and have grown into a crazy collector.
Best regards
Tyrone