1 On average, plan on spending around $0.70 to $2 per pound for spaghetti squash. 2  Typical spaghetti squash will cost around $3 to $6 at your local grocery store. The website Spartan-living.blogspot.com shows this very distinct way to cook pasta with the spaghetti squash. 2  It also list down the price of the ingredient at a cost of just around $1.58 for a 2.5 pound pack.