I can give both perspectives on this:
As a consumer, I hate shipping costs! So, I price compare when ordering from companies and include shipping in those comparisons. Like books! Since I read so much, I order $25 or more from Barnes & Noble to take advantage of their free shipping. And I will not order from a company if I feel they are charging way too much (i.e. $5 for a stamped envelope).
As a company owner, packaging orders is very time consuming. Shipping/handling rates might include costs for hiring someone to package orders. $1-2 for handling is reasonable in my opinion. Postage, packing materials, gas for the trip to the PO or pick up fees that UPS, DHL, or Fed Ex may charge is probably included in shipping costs. Some companies do charge exact shipping, but sometimes that can be difficult (especially now with the shape based postage) so I think many prefer to do a flat rate.
I was telling a friend that USPS is going to shape based shipping and would soon be like the other shipping companies because many people prefer to pay bills electronically, email is great, and low or no cost long distance is available in many areas. This is probably cutting a big hunk out of profits for the post office. People will always send packages though. Gas prices don't help either.
I did read an article about how postage rates are still below inflation. The article talked about the forever stamp and how it might not be worth it to hoard them since postage was considered to be "low". Haha! Kind of like gas prices a few years ago when they talked about how gas prices didn't keep up with inflation. Well, they're keeping up now! Can you tell I'm not happy about these prices?
The article about the postage was
here.