There are many factors that affect the cost to actually ship something. Some vendors use multiple methods often determined by availability, package size and weight. For small packages especially if the item can go in an envelope US Post Office could be best as the rate does not change based on distance. The other common carriers use weight, package size, even value as part of the total cost. If the carrier has to pick it up may also have an effect. As an order is bult up if the box has to change size the price can change drastically. Also, at some point the box has to be paid for, along with the dunnage, and at some point the person packing has to be paid. For vendors shipping and handling is either a cost center or they turn it into a profit center. When placing orders I do give thought to keeping orders small enough to go priority main. Even from GoWesty I usually get those orders in 3 days. UPS Ground is always 5 or 6.

As for Amazon, I give them a lot more business than I care to admit and yes I use Prime. A lot of their stuff is delivered overly packed and it seems most orders come from multiple places. More packing and the environmental impact of running those trucks. They also use multiple carriers along with their own services. A Makita weed Whacker was delivered by the post office! Go figure. For business support getting reports, and handling returns they are the best. For delivery they are usually faster than ordering though the local parts stores or dealer networks.

Dennis