Do you use the eBay shipping calculator or do you normally set a fixed shipping cost?

If you use the shipping calculator, is UPS still an undesirable option?
If you set a fixed price, do you use a ZIP code of the furthest distance you might ship it to and is Fedex still the preferred method?

I have a box 35 X 28 X 9 inches at about 16 pounds. It's only a frame. From the west coast to east coast, I'm getting quotes of $70 (Fedex) to $100 (USPS).