Second, if an item is only worth $3, don't sell it on eBay. It's more cost-effective to throw it in the trash.
If you're going to do this frequently then buy a shipping scale.
If you're doing this infrequently, then just figure out which size of USPS flat rate box the item will need and charge appropriate shipping.
Last time I sold something on ebay (years ago) they had a tool that would let the buyer estimate their shipping charge based on their zip code - ebay automatically charged them the correct shipping amount.
Find a zip code that is a zone 9 from you (99901 should work) and use that to estimate shipping. Then divide by .86 and add 30 cents to understand what they actually need to pay you.
I basically just paid this girl to take my jeans.
a flat rate box is only $5.80 - your fault for being too stupid to know what your USPS shipping options are.
I see a lot of people offering free shipping on things on ebay. I have done this, and every time, I seem to get someone in a zone 6 (California). I just sold a pair of jeans that were expensive. The jeans went for 2.99 which was the minimum price. I put shipping of 5.00 but the California resident will end up costing me over 10 because I live in PA.
How do people make any money at all on ebay anymore? If I put 10 in shipping no one will bid. I don't own a small scale at home. Ideas?