This is written by Chris Hinson, the admin at RPG Auctions on FaceBook and

rpgauctions.com

There are basically 3 ways to buy postage.  1. Go to the post office and buy it at the counter. 2. Go to the USPS website and buy postage online (of which you can buy stamps or click-n-ship). 3. Use software to buy postage.

Each of these three methods have different rules and different costs.  The counter is most expensive, USPS website is a little cheaper on certain classifications, and software "can" be the cheapest, but you have to research each one.

There are literally HUNDREDS of different types of software, and they all have their own little "fees" associated with using them.  Some pass along those fees to the customer in the form of a premium on top of the postage you buy, and some charge you a monthly fee to use the software (in which case the postage fees are probably less).  And one I know of just buys huge amounts of postage and uses credit card cash back as profit for them.  PirateShip has the lowest fees I've seen but they are a little lean on software features, so I've personally chosen to use ShipStation (NOT PayPal "powered by" ShipStation...I'll explain more below.)  I've compared rates between the two (PirateShip and ShipStation), using a spread sheet of thousands of addresses and zip codes and the difference in price was worth the features for me (maybe not for you...make your own informed decision). I'm not promoting either one, just telling you which one I use and why.

USPS has a seasonal peak season cost ADDED to the postage costs they already increase each year.  So...after the seasonal peak fees drop (after Christmas) you'll see the new yearly rates go up as well (most likely)...but these are two different things.  Here's a link for 2021's extra seasonal costs that you will be expected to pay: https://www.shipstation.com/blog/usps-holiday-surcharge/  These fees are on top of the regular USPS fees, and the software you use "should" technically have these already, but if you went with the dollar tree version of software, you may be risking not having the latest costs updated.  My information is that PirateShip and ShipStation both have the additional fees already ready to go because they both have connections to stamps.com (a preferred broker for USPS postage purchases).

PayPal USED to have an API connection to a shipping program and label print and it was integrated with their order processing work flow.  However, this link which was previously called "SHIP NOW" has been removed and now points to a page that asks you to sign up for PayPal Shipping "Powered by" ShipStation.  This means that PayPal is now using the ShipStation enterprise api and software to sell postage and print labels.  This is not exactly the same as having your own separate ShipStation account.  You "can" go to ShipStation and purchase an account and get their lowest rates, but it comes with a monthly fee.  PayPal has decided to not own the shipping software process.  They are however leveraging "some" of the ShipStation technology.  Consequently, there is an up-charge on the postage you buy through PayPal now.

If you observe closely, eBay is charging as much as 18% on fees now, so shipping charges may not be your actual concern as to the cost of doing business there.  

What I elected to do is have a ShipStation account (directly with ShipStation) and I hooked it into all of my sales channels, integrating the whole order process: eBay, PayPal, LostTomes, RPGCrate, RPGAuctions, and KickStarter.  I sometimes get a little hiccup when I add a new channel (working out the kinks between the two systems) but this has afforded me view and control of my costs in one place.