[agencies]

If it were easy/cheap enough to host, can a model like shared game servers or web/email hosting work? People pay $20 a month without thinking for web hosting. What does it take to make "search hosting" a thing, where cheap search hosting companies can crop up both at the low end with bare bones offerings and others climb up the value chain with offerings like squarespace...

[marginalia_nu]

Cheap is probably a bit out of reach. I think right now, for hosting something like my search engine, you're looking at either a one-time cost of around $5000, or $200/month in server rentals. Maybe you can bring that down with the economies of scale, but it's never going to be anywhere close to $20.