Maybe I’m on the outside here, but if a plugin that costs $179/year is a core part of your business model, you maybe you should consider the ongoing cost of updates and support as part of the viability model.

When we recommend plugins to our customers or include them as part of website builds we build the ongoing cost as a part of our proposals because you never know when a critical core update is going to break something or it’s more cost effective to drop that ticket to support then try and muck around and find the answer yourself.