When talking about environmental needs, some floors have unique requirements involved in how they’re laid.
A self leveling floor may need rises, slopes, or other elements as a part of the final result. This can impact cost.
Additionally, if the leveling involved takes place in an area that’s difficult to work in, this may adjust the compound used or the labor rate.
This kind of element is rare, but does happen.
Beyond this, if you are floor leveling in a way that requires a more fundamental movement of the floor itself (mudjacking), or if the condition of the soil beneath is questionable and may disrupt the quality of the leveling in the long run (replacement), you may need different approaches that stabilize your floor before progressing to any self leveling process.