The high price of X1000 was without development costs, just part prices and production costs? And yes you can only estimate them (often based on experience) but somehow you must cover your expenses like marketing, sales and development. So based on a estimate you calculate how many devices you must sell that your costs are covered. That is at least how I learned price calculation.
there was something like £1699 on one of a-eons sheets I think but we will not know propably before you really can preorder. And Tabor is nothing more than embedded hardware running a obscure OS (not to mention the problems in the design). As long as it is not really cheap it will become a failure. I think one of the leading AmigaOS devs mentioned that work on Tabor will not start before X5000 is completed so it does not like there will be anything available in next months and hardware is not becoming better in 2017 or 2018. I hope for Trevor he can afford the losses.