In principle, there's a limit to how much can be charged for film, given that there will be a fixed cost to make a batch and that it has a shelf life. In other words, there's a practical minimum number of rolls/sheets that can be made in a batch, and it has to be sold within some sensible time limit. If the price is too high and people don't buy enough of it, the maker would end up sitting on old stock (or paying additional ongoing storage costs to keep master rolls in deep freeze). There's no point in growing 100 apples and pricing them such that the market will only buy 50 before they go off.
There always seems to be somebody speculating that some new film or other is repackaged Ilford stuff, and Ilford consistently state that they never do this. I suspect that some films are made with Harman as the contractor, and it's likely that the actual manufacture is being done by the operation called Ilford (unless Harman have other operations that have film manufacturing facilities). From the blurb on Silverprint's page for Kentmere 100...
The Kentmere range is owned and manufactured by Harman technology and follows the same high quality processes that are used to make all ILFORD PHOTO films and papers
It seems to me that any film being made in the UK that isn't branded Ilford is either some Harman product, or a customer-specific recipe made under contract by Ilford, via Harman. If that's what's happening with Acros II, then it's interesting to note that Fuji appear to have decided that manufacturing it themselves is no longer economically viable. With only one normal B&W film left in the range, it's cheaper for them to get an active coating line elsewhere to do the manufacture than to run a full B&W line themselves.
The key thing in my mind is that, perhaps with a few exceptions, the film makers have scaled back in terms of how many coating lines are running, and what films they make on each line. It's entirely possible that the global market has shrunk to the extent that a single line constantly manufacturing one film would lead to oversupply on the one hand, and a resulting increased cost of manufacture for the amount that's actually sold. It looks like the way forward now is to set up a line to make enough film of a given type to cover a certain shelf life, then reconfigure the line to make another film type, and so on. Less lines overall, but those that exist spend more time making stuff that actually sells, which means the cost to make a given batch is less than running, say, an Acros line for one month a year and keeping it functional but idle for the rest of the year. What it also means is that the cost to manufacture increases due to reconfiguration every time you change recipe - chemicals and ingredients need to change, the process needs to settle, and tests need to be done to ensure that the current film being manufactured meets the specification. Then you manufacture in bulk to cover a given sales period/shelf life before stopping and repeating the reconfiguration process for another film.
What this all means is that the cost to make a given film still goes up a bit because of the additional time taken to reconfigure the line, but whether the cost of Acros II will be sky high remains to be seen. On the one hand, Ilford may have a vested interest in protecting Delta, but it could be argued that the two can coexist, depending on what photographers want. It's a subtle balance between how many former Acros buyers would switch to Delta, how much Delta Ilford reckon they can sell if they didn't make Acros II, and whether their manufacturing would have slack time as a result (thus increasing the cost of Delta). It looks like they reckon it's viable for them to make both. It has to be remembered that Ilford/Harman are a manufacturer and wholesaler - it doesn't really matter to them what specific recipes they use, or what's printed on the packaging. Their interest is in selling large batches of film to retailers and distributors while keeping the lines busy.
Given busy manufacturing lines, two things could help to keep the retail cost within sensible limits. Ultimately, there is only so much film that is going to be purchased globally. The pricing has to strike the balance between maximising revenue while not pricing yourself out of the market and sitting on aging stock. The other is that there is still competition outwith Harman/Ilford. It's tempting to think that a cartel could form, where the pricing of Acros II and Delta shoot up, but they (Ilford/Harman, and Fuji) still have to compete globally with other makers. And, the retail prices of all films still have to be such that film photographers will buy what is manufactured - they can't just charge what they like because film itself is in competition with digital.