To answer this, you must break it into two parts: the cost of digging and the cost of finishing. The digging cost is based on cubic yards, which is a volume measurement. How many cubic yards of dirt do you need dug? If you convert your measurements in feet to yards, then multiply them together, you will get the number of cubic yards. Multiply that by the cost per cubic yard and you have your digging cost.
The finishing cost is easier: you don't care about the depth of the cellar and the cost is in square feet - an area measurement. Multiply the width and length of the cellar (in feet) together to get the area in square feet. Then multiply that by the finishing rate.
When you add the two parts together, you get your final quote.
Stephen La Rocque>