I am fortunate enough to be on the $10 plan, but given how little traffic my site gets cutting it in half with the smallest DO box would still be nice.
You could move from Ghost Pro to another Ghost provider without being completely manual. A quick google turned up FastComet at $2.95/month. Page claims 1-click Ghost installation, easy Ghost upgrade service, and daily/weekly Ghost backups.
https://www.fastcomet.com/ghost-hosting
Yay open source!