Shipping cost is only high if you live far away. It's crazy but true.
Not crazy at all. Have you driven 2000 miles lately and bought several tanks of gas?
For small keyboards, packing in neat little boxes is fine, but ancient IBM iron usually ships cheaper at flat rate.
You have to learn the ins and outs of all the carriers' voodoo calculations. I shipped a moderately large box to California recently via UPS cheaper than the PO rate, I was a bit surprised. I understand that FedEx has an ebay-related rate that is very good, but FedEx is rather inconvenient for me.