However, I don't think that end game is the first use case for an RFID solution - inventory monitoring/LP/loyalty can demonstrate ROI long before the checkout lines are removed. For those use cases, the unit price needs to be much cheaper, but an order of magnitude improvement might be right.
I have skin in the game on the loyalty part so I will abstain from speaking on that.
Coming back on your thoughts about inventory, the birth of Embisphere, the RFID company I spoke about earlier (and the reason why Decathlon started to use them), was solely the invention of a "racket" for fast instore inventory
http://www.embisphere.com/en/rfid-products/embiventory-power
Other uses (checkout, LP) were almost an afterthought. The sole gain on speed and accuracy of in-store inventory was enough to decide Decathlon to add RFID chips on all its inventory and Decathlon inventory is massive ! They are in the range of 30-70k active SKUs, with sometimes hundreds of thousands units of stock. Sell that in hundreds of stores worldwide, add the warehouses in every country and the manufacturing facilities in China, and you end up with millions of euros of investment just for that damn inventory ;-)
It would be lovely if you developed an in-store navigation capability. It's so frustrating to run into a store to pickup something, and not be able to immediately find it.
The results of periodic scans should provide a decent point cloud that could be used to determine shelf/aisle geometry without a blueprint. Foursquare uses this sort of approach for its interior mapping process, but they can't tell me where to find the bean dip. There are multiple obvious ways to monetize that dataset including simply selling it to Foursquare.
In-store location of products is deeply linked with very complicated discussions between retailers and product manufacturers.
Moreover, facing is a very strategic part of retail and I doubt retailers would be happy to release their facing strategies to outsiders or competitors.
Even inside a retailer's organization, several opposing views exist, between maximizing breadth of product range, giving prime exposure to the private label, etc....the equation they have to solve is very complicated and I don't think there's an ideal solution to this. A retailer facing strategy is linked to its core values. It has a direct impact on its bottom line and an indirect one: the consumer's unconscious perception of facing "strategies" is probably very significant.
I have reasons to believe several ink manufacturers/printers are working on an order of magnitude less per tag.
But are you so sure that 10 cents is too much?
What do you think the gross margin on that can is ? ;-) What do you think the net margin on that can, once the checkout lines (and their personnel) are removed, would be?
If a stitched RFID chip on a 2€ thsirt is currently cost-effective for Decathlon, I see no reason why printed RFID tags would not be cost effective in the very near future, if it is not yet the case (and once again, I have reasons to believe it is almost already the case).