I'm completely ignorant of retail pricing, but I know at the grower level, I've never seen 'Missouri' listed at a premium. One grower I know is going to, or has, pulled it from his list due to poor sales. Seems everyone claims to want something new, but always opt for the more well known name and in this case it is really short sighted, imo.
Well, I don't consider them different forms as much as sources of varying germ plasm, but as far as ampla goes, I use the Mexican one, one from a Florida collection and in the recent shipment I did get some specimen from one of the Carribean Islands.<g>
White colorata tubers just as abundantly as the blue, which is why I'm surprised to hear it is scarce.
But I'm on my way out the door to head to St Louis, so I hope Lorenzo isn't planning on coming too soon.<g>