I recently sold two Tektronix plug-ins to someone in NJ via the USPS.
I packaged each plug-in in its own sub-carton and packed them in a
well-padded single larger carton. The package weighed a little over 18 pounds.
Here are a couple of things I learned:
--Parcel Post no longer exists for general mail-- this package shipped via Priority mail
for $30.00. There were no less-expensive modes.
--The outer double-walled carton once held expensive brandy. I partially obliterated
its original markings and bar codes. "Not good enough", said our postmaster,
"Everything that looks even remotely like an address will mess up delivery." He
proceeded to completely overmark everything.
--On a different topic, I learned that small component-class envelopes
get screened for flexibility and thickness. The envelope and contents may weigh
only a couple of ounces, ($1.30 postage maybe), but if it's too thick (over 1/4 inch)
the postage escalates to $4.00 or more.
Why not use UPS or FedEx? I'm located two miles from a US post office
and 10-14 miles from UPS or FedEx pickup points. I figure 20-28 miles round trip.
That's most of a gallon of gas ($3.40 st the moment).
I've had good luck with USPS shipments-- don't skimp
on the packaging.
Hope this helps, and 73--