How much money would a plumber charge to dig under a 1 story home that has 2 rest rooms and kithen.start @ main and work your way to the house.cut and leave @ least 2 to 3 inches of cast iron pipe under foundation. Then use a rubber transitional coupling for cast iron pipe to pvc[abs]pipe.then cont. with new abs plumbing.when plumbing is complete, install some 6 by 6 wood studs to use as support under foundation. No back fill

This is too broad of a question to answer...

As we always suggest, do this: Call 3 local licensed plumbers from Yellow Pages. Have them to come over, inspect your house and give you free written estimate. Ask lots of questions. Compare estimates to get an idea about the price. Select one of them and award the contract.

Hope that helps. Milo