For example, the epoxy that AeroMarine puts out for marine and aircraft coatings is about the same costs as an expensive outside house paint. These are clears.
It’s always best to look at other actual user reviews if they are available. User reviews and first hand experience on longevity of any coating are gong to be your best bet for a positive experience. Read through any negative reviews and look to see if they were user error (applied without proper surface prep) or legit.