Really, really good music, but you just won't be able to make it PPP. PPP stands for "popular, platinum, or past 100,000 Google search results". (Paganinio made that up.)
Here's some examples that I know:
Maudlin of the Well - Bath 59,500 Google search results
MAUDLIN OF THE WELL - Leaving Your Body Map 10,600 Google search results, that is less than one fifth of Bath
Here's some formulas to make such an album:
1. Obviously, you have to make a prog album. Prog albums automatically sell less.
2. Add death, doom, or black metal elements. Black metal used to guarantee unpopularity, and in the recent years death and doom metal seem to have caught up. They are just as unpopular as one another.
3. Don't let Steven Wilson or one of the big guys touch your career. Opeth failed to maintain their underground status thanks to Mr. Wilson. Do you really wanna end up like them? I don't think so.
4. Don't let any websites know about your album, with the obvious exception of ProgArchives.com. Actually, ProgArchives should always be the first Google result of your album. Maudlin of the Well are the master of this.
5. Finally, it's gotta be metal! The math is simple: Progheads, though rare, will buy a prog album, metalheads will buy a metal album, but who the hell is gonna buy your prog+metal album?? The chances of someone loving both metal and prog rock, are miserable.