I looked it up*
https://blog.kagi.com/status-update-first-three-months#kagisearch
It's $.0125, so 1.25 cents not double digits like I thought. They also average 27 searches per day per user. So an average of 821.25 searches per user per month, meaning a cost of $10.27 per month.
It's probably as good as we are going to get.
The best options would be an open source, donation supported search engine, but the money required to host/develop that is immense.
We are all freeloading off of Lemmy right now, unless you are donating to the people who are running the servers. The cost to run a search engine is much higher though -- kagi pays (iirc) double digit cents for each search, even before development costs, with the average user doing 700 searches a month. The costs are way higher.
It's also privately owned by one guy, so it doesn't have to submit to investor pressure.
Steam, for example, is basically a monopoly for PC game sales, but hasn't enshittified because it is privately owned.
Is there anything even wrong with the default Google file manager? It works pretty well from my experience