One odd thing that maybe the post office will change is that for light-weight first class parcels (that most of us use) it is 6-cents more expensive now to generate your own shipping labels on eBay-PayPal than it is pay for it to the clerk at the post office. It has to do, in part, with the fact that discounts are not offered anymore, on first class parcels anyway. It is discussed on the eBay Shipping Discussion board, here:
http://community.ebay.com/t5/Shipping-Returns/Postage-discount-not-applying/m-p/25047107#U25047107

The two tables below are from good old Notice 123 • Effective January 17, 2016 price list:
http://pe.usps.gov/text/dmm300/Notice123.htm#1118064

The post office clerk uses this old table (carried forward in the Jan 17th price list). See, we pay $2.54 to the clerk for light (1 to 3 ounce) parcels:

But on-line, we pay $2.60 for 1 to 3 ounce parcels:

The important thing for us is that before this price change, we got a discount if we computer generated our 1 to 3 ounce parcels -- we got a 50-cent discount; we paid $2.04 instead of those who paid $2.54 for the same thing to the post office clerk. .. ..... Now we pay $2.60 on-line for a 1-3 ounce first class parcel, and those who pay the clerk for the same thing pay $2.54.

Robert