This free scrap gold calculator will calculate what your scrap gold's actual current full market value is (i.e. retail prices).
If you want an idea of how much you might be paid by a refiner for selling your gold simply multiply the result you get by 0.8 for < 1oz., and 0.9 for > 1oz. and you will have a rough idea of what you should, on average, be getting from a refiner for your scrap gold.
You may also want to look into local refiners if you live in or near an urban area.