People talk about this as if it's an action you can take. The title even uses it as a verb: "open source" it. Is "open sourcing" even the decision of the developer, in reality? Sure, the developer can decide to release the code as open source. That's fine. But to make an open source project requires a lot more commitment than that[1]. An open source project is kinda like a startup. You need your product (the code) yo…
iOS currently makes for a good example, because all it takes for some old apps to use the Retina display is to recompile the very same source with newer dev tools. Sometimes it just takes that, or a small fixes to make software run on a new OS.
I'd pay more for software if the authors promised to open-source it the moment they drop support.
( Of course, the App Store has a problem similar to Ruby Gems - it is hard to transfer control of the main repository.)