people pay for a search engine, they would subscribe for a browser if it does what they want
if Mozilla bundles a private, secure and well packaged browser with a good search engine and this browser performs well while still providing the current version for free, there's a certain minority who would be compelled to pay for it
atm, a browser and search engine is the major gateway to the internet, google has always done that at the cost of the user being a product, but it is now fucking that up and an alternative is needed, Mozilla could and should step in for that
maybe firefox forks already do the trick for you, i've heared there are plenty free ones.
no need to pay, but maybe donations are very welcome.
also a complete open source solution that is ready to be compiled by anyone could also be patched by anyone for himself to disable a feature heshex dislikes or such.