This message is from someone who runs a business and who has worked in the mail order business - from pulling orders, to shipping, to taking orders, to customer service, to working the financial end of it. Recently.
Please don't complain about paying regular shipping costs. Please, DO complain about paying excessive shipping costs and/or handling fees. However, expect a handling fee if you return a used/dirty item that you just decide you don't want any more.
You can look up rates on USPS.com (US Postal Service) and UPS.com (United Parcel Service). Shipping is based on weight, package size, merchandise value, and where the package is being sent.
Remember, if you get "free" shipping, the shipping costs just get added on to the price of the merchandise to cover the retailers expenses. Shipping is expensive now. Period. (Shipping to Hawaii, Alaska, Canada, and Mexico is incredibly expensive. Shipping overseas can cost hundreds of dollars.)
Also, please note that if a company sends something by US Postal Service and the item gets lost, the retailer gets stuck for the cost of the lost item - even if it is insured. The Postal Service almost never pays on a claim. If they do pay it can take a year or longer for the sender to be reimbursed.
Shipping is a huge expense to a company. There truly is no such thing as a free lunch - oops - free shipping.