Salem

I read in the Salem wiki (http://salemwiki.info/index.php/Coffin_Plank).

A nice late game source for using it as a resetting inspriational when getting higher levels of Hammer & Nail.

Does that mean that if you have used the same Inspirational several times (which drives the necessary inspiration cost up), then after using this inspirational it starts again with the initial inspiration cost?

Is there a list of all such inspirationals or is this displayed somewhere in the ingame description of the Inspirational?

Does anyone read those?!
Wiki is written by players and often inaccurate and not up to dated. I believe that is something that was left behind by from a long ago when system like that existed.

Indeed, a leftover from an old studying system. I removed the reference.

FYI, the old system had the same base as the current one: as you studied multiples of the same inspirational, its cost went up (more specifically, its effectiveness lowered). But rather than being counted for each inspiraitonal separately, this was a global counter: if you studied an object you had already studied before, it would lower the effectiveness multiplier. Study a new object, and the multiplier reset to 100% -- hence the explanation you found on the wiki. Some history for ya.