Hello Mortgageman and Welcome:
Does the city have a minimum ground clearance rule? FHA calls for 2' minimum but I personally would say yours is OK.
If you can 'beef-up' the foundation without having to raise the house first, you can get by with simply digging down to their recommended depth, pouring a footer and build back up with concrete blocks. The digging would have to be done by hand and the concrete and blocks would need to be done in two stages, filling in alternate openings (to keep the house stable), then come back and fill in the remaining spaces.
It will be a tedious job and, if the house has to be jacked up, it multiplies. To hire the job done will run between $15,000 and $25,000. I know that's a broad range but there are so many unknowns. This is just a range to let you know if you're about to be ripped off.
Ask the contractor for references and pictures of previous jobs and check them out. Talk to the customers. Verify worker's compensation and liability insurance.
We would appreciate a pictorial progress of the job and we wish you the very best on the venture.