Where is the water coming from?

We recently lost a buyer for our house because the home inspector determined our crawlspace cement walls were "saturated" with water. 80% was the reading he gave.

There are salt lines along the cement that indicate there is water but the walls are cool and dry to the touch.

There is no water pooling anywhere in the basement and we have had a desert dry summer.

House is on a steep grade from front to back-where the problem is. Cement is dry under the front of the house.

No obvious plumbing leaks that would provide that much water.

Three cracks in the foundation with same salt marks indicating water- no pooling near the cracks.

I had a representative from a company that specializes in basements come to the house and concur with the Home Inspector. He offered a 12 thousand dollar solution involving a patented interior installed weeping tile and sump pump system.

My question is where is this water coming from that my walls are soaking up?

Will investing in the system actually solve the problem?

Is it even a problem at all- other than the cracks that can be individually filled? There is no mould and house is 40 years old.

Any insight on basements in this condidtion would be appreciated.