In this project I was tasked with fixing their pricing issues, based on custom prices per zipcodes. The issues were due to the weight of the coolers for some reason bringing the wrong shipping price through the USPS API being used and also they wanted to offer free shipping on the coolers after a certain price. That shouldn’t have been happening and USPS said there was no issue from their end, I needed a customized solution. Luckily they were using WooCommerce as their e-commerce solution. I wanted to install something that would work well with that which led me to the Table rate Shipping plugin, this allowed me to solve their shipping issues by setting custom rules and flat rates for the problem coolers depending upon ranges of zipcodes covering the US.
I also had to contend with how the custom shipping rates affected the total once other items not covered by the custom flat rates. I solved this by setting per product rules and creating shipping groups which allowed for the proper shipping price to be set no matter which products were added to the store.