Gave a price to dig a hole along a foundation of a house. Foundation repair people are going to have to rebuild a basement wall that is caving in. I am to dig down about 12 feet deep along the foundation, about 14 feet back from the wall; about a 20 foot long hole. Back fill 2 feet of crushed stone. I am figuring on using a 15,000# excavator for this seeing as how deep and far I will need to reach. Any 2nd opinions?