One of the bigger questions I have about the potential shift to requiring services is the fate of shared hosting deployments of MediaWiki.
Seems like an opportunity. "Deploy your MediaWiki-Vagrant instance to our cloud infrastructure cheap." It's not $2/month, but Digital Ocean can host a 1GB VM for $10/month. Maybe https://atlas.hashicorp.com/ will host vagrant boxes cheaper.
Docker allows many Linux containers on the same physical system which should lead to lower pricing. Some MediaWiki dockerfiles install Parsoid and nodejs as well as MediaWiki and PHP, e.g. CannyComputing https://github.com/CannyComputing/*frontend-mediawiki https://github.com/CannyComputing/frontend-mediawiki* , or you'd have separate container for each service. I can't figure out the pricing.
-- =S Page WMF Tech writer