The nasty part of that change is that apple just changed the way subs work ,and that now the développer can raise the sub price silently .sneaky really .
They can up the price of the sub. I don't object to that. Likewise, I can always just cancel my sub. What I do object to is upping the price without informing us ahead of time. I had a neighbor who got pissed that his ISP upped his internet service rates without telling him. He had to check his bill to discover that. He got so pissed that despite the ISP giving him incentives like discounts for the next few months, he got fed up and just said "Nope! Cancel my service!". Me, email us to notify a change in prices and plans, and let me decide from there.
I understand the concerns of app makers, and yes, they have to make a living. But this is NOT the solution. Allowing users to try the apps (not speaking about freemium here), allowing special sales or promoting them (like Steam), allowing true upgrade paths (reduced prices for owners of a previous version), ... this should have been part of the platform from the start. Building a healthy relationship with your customers is what makes them get back to you when you have a new version or a new product, or simply when they can afford it.
Consumers of mobile markets are VERY skittish about freemium models (yes, some of them are truly awful, but I feel consumers don't spend the time to research what's truly exploitive, vs. something that's akin to the shareware models of computing in the 80s and 90s).
Promos and sales on Steam have devalued some of the wares there. FWIW, games are entertainment and strictly optional, whereas apps used for work and making a living have a much easier time charging premium pricing. However, Steam games tend to be much more expensive, so a dev would rather have a 10% sale off on a $20 game, vs. a $5 game that sells for full price on mobile markets.
"Upgrade paths".. does this exist for the iOS App Store? IIRC, no? In the past, the closest thing they could do is just to release a 2.0 of their app, and charge for that since Apple didn't allow users to charge for updates. Oh, they could also introduce it in the form of IAP, but that might have issues for newcomers who should be on 2.0 version of an app to start with