Project managers utilize a number of cost-estimating methods. What cost-estimating tools should be utilized in an eCommerce project for a large animal hospital?

• What method of cost-estimating is appropriate?
• How closely do they resemble the methods found in the PMBOK Guide? How effective are they?
• What is a three-point estimate? What is the formula for the three-point estimate?
• What is a parametric estimate and when is it used?
• What is an analogous estimate? How is it different than a bottom-up estimate?