Is $10,000 to add tall industrial jacks to the basement to strengthen weak supports a fair price?

My girlfriend bought a house that is over 100 years old. Before buying, two inspectors said the foundation looked good despite uneven floors, but one was recommended by the realtor, which now makes me suspicious. After a year, cracks are forming in the walls, especially on the staircase, and my girlfriend feels the foundation has problems. The wooden supports in the basement do not seem sturdy. We had three companies do free inspections, and all confirmed weak supports, proposing to add tall industrial jacks. The prices ranged from $10,000 to $25,000. I've agreed to help pay, but I'm considering paying $400 for an independent structural engineer to assess the foundation and review the proposed plan, as I want an unbiased opinion. My girlfriend thinks I'm being paranoid and that we should proceed with the repairs without further inspection, as she believes the house needs this. I informed the foundation company of my intention to get an engineer's opinion, and they were understanding, which I took as a sign of trustworthiness. I've started looking for structural engineers on Google Maps and calling them.