Why are the shipping costs shown when creating a listing different than what is charged?

[shorebetz]

I've been selling Blu-rays and DVD for the past few months. When creating a listing, I enter the weight and size of the package, and I select the shipping service. The price shown for shipping is always a dollar or more less than what I actually have to pay when purchasing the shipping label through eBay. What gives?

[nobody*s_perfect]

I checked a couple of your listings. They are offering shipping in a "First Class large envelope."  But (1) eBay doesn't sell postage for First Class large envelopes (AKA flats) because it doesn't include tracking; and (2) your items are not eligible to be mailed through that service anyway, since it requires that the envelope must be flexible.  

When a listing offers a service that eBay doesn't sell postage for (such as Large envelope) but you try to purchase postage through eBay for that item, the label purchase process switches over to a service that eBay does offer. So it's not surprising that the prices don't match.

You should switch your Blue-ays and DVDs to shipping via either Ground Advantage or Media Mail.