PSA firearms packaging is always great, their ammo sometimes loose, but their small items too often are packed in wasted oversized boxes. Example today my order for the “AR15 quick repair kit” a $9 item with a few pins and small springs contained in a 2" ziplock, arrived paced inside a 5x5" box stuffed with heavy construction papper. You could have fit 25 inside, instead the item could have been shipped in a small padded envelope. Mind you Im not complaining except that PSA is wasting money or someone isent doing their job. No wonder shipping cost me almost as much as the item lol. Anyway Im just saying not criticizing a suggestion.
They are buying and shipping in bulk just like everyone else. They buy their shipping supplies (like boxes) in bulk also. I had a thumbdrive arrive via amazon in a 8x11" envelope.
as long as there’s a sticker or some other bling in that box, I’m good 
It all comes down to speed.
I spoke with someone that worked at Amazon packaging shipments. I asked the same thing. Why such big boxes for small items? Isn’t it a waste? They confirmed it’s all about speed. They are graded on how many shipments they fill per shift. Amazon (much like PSA) deals in such a high volume that it doesn’t affect shipping rates for the company. They have so many things to box up and ship that speed is the key.
If a packer has to turn around and grab an appropriate sized box it takes a few seconds extra. Times that by hundreds of shipments per day for just that one single person and it slows them down. So whatever box is directly in front of them is what gets used.
Speed, speed, speed. Get it out or get moved off the line to a lower paying position.
That pretty much sums it up. I’m sure it’s the same scenario at PSA.
I can’t order just one item and pay 8 bucks for shipping. I’ll find something I need just to feel like I’m getting my 8 bucks worth
There’s no kill like overkill!
One thing forgot to mention. Ebay which is made up of small vendors and usually include free shipping are very efficient when it come to packaging. You’ll almost never see an oversized package. My point it can be done and does save shipping cost for both the vendore and customer. Conversely disproportionate shipping charges for small items in oversized packages are part of the big business model and profit margin IMO