Survivalist market

There are "survivalists" who would like a home that could have a good chance of surviving various potential disasters like breakdown of society, nuclear war, disease outbreaks, etc. A seasteader could get their own food by fishing, hydroponics, and maybe aquaculture. A supply of nutrients to last many years is not very large. A seastead could stay isolated from other human or animal contact to make it impossible for many types of contagious diseases to get to it.

Solar panels can provide power for 25+ years.

A survivalist on a seastead out in the deep ocean sort of has a big moat around him making attack from hungry people less of a problem.

So it may be possible to market a seastead with a certain set of equipment to survivalist.