Thanks everyone for all the responses!
I do print my own labels through Paypal currently, and that saves time and money. When I want to set up a carrier pickup through the USPS.com site, I have to have at least one "expedited" package (priority, express, etc) for them to pick up other packages like first class and parcel post. I cannot set up a carrier pickup with only first class packages.
For those that have a carrier that picks up your first class packages from your home, did you coordinate this with the carrier directly? In my community, we dont have individual mailboxes, we have a central group of mailboxes for my whole block (similar to what apartment buildings would have). Which is why it is too small for my packages. If I had a regular mailbox, I'd be able to fit my packages in there.
For my costs, I factored in my gas expenses, since gas is not cheap now...the nearest drop off location is a 10 mile round trip. Not terrible, but you'd be surprised when you look at how much that amount of gas costs to get you there and back. Im not even factoring in my travel time...and most of the time I am only sending 1 or 2 items. My bubble mailers cost me less than $0.25 each...but again, USPS provides free Priority bubble mailers, boxes, etc, which I order online and they deliver my supplies right to my door.
Very interested to hear everyone's thoughts on all this. Anything I can do to streamline my little process and make it more cost/time effective can help.