Even with the small one
USPS boxes are difficult to get from out of state unless someone there will vouch for you. I've done it once while moving and it was a PITA. Get a box from a store instead.
Remember to download your Use Tax form from the WA state website and self report the sales tax you owe if you buy something in Oregon and bring it back to WA. Think I'm joking? https://dor.wa.gov/sites/default/files/legacy/Docs/forms/UseTx/ConsumerUseTxRtrn.pdf
Amazon locker
There's something called Amforward. I bought a TV, and they charge $8 for receiving the item
Amazon
Locker