I think this proving out the concept. A dev board costing. 150 doesn't matter for professional projects. It latters for tinkerers. What matters is unit price for desired qty.
And this has 4G/LTE (because it is a smartphone) so comparisons to base RPis are largely irrelevant.
And in industrial embedded Linux stuff there is essentially no correlation between price and performance. Most don't need performance and they aren't really cost-optimizing this bit of the production line very hard. It just needs to be certifiable, reliable and replacable.
I do hope they come down a lot in price and prove this out over many more phone variants.