It sounds like you may be getting ready to sell.
If that is so and taking your realtor's comments into account,
leveling may be too much work.

I think you could jack the frame without too much trouble.
We have a three story house.
We removed some siding & scabed blocks to the side of studs.
Placed double 2 by braces at an angle and drove the down end toward the
house with sledges.
This lifted the frame enough to remove a bottom plate and insert a new
one.
This approach should allow you to place shims or concrete below the
bottom plate to level.
TB