1982 was after the fall of diamonds from a price bubble of the 1979/1980 era. Some retailers were giving realistic appraisals back then and others were doing what they could to mitigate the lowering of most diamond values from the 79/80 period by giving inflated values.... Folks so much expected diamond prices to keep rising and many sellers were scared to admit that the highest quality diamonds had fallen abruptly in value. It was not their fault, but they were uncomfortable with the situation.
If you run a pricescope search on the quality and weight of the diamond you have you will get a low retail number for it based on the current market on the Internet. If you want what an AGS retailer would sell it for in a B&M store, you will need to add 10 to 50 percent more to get to a relatively realistic amount.
There are some B&M stores willing to deal at Internet level mark-ups, but few are willing to brag about it. They truthfully cannot afford to sell for virtually no profit. The Internet is creating a very difficult environment for traditional retailing. We will see some major changes in the coming years. Not all change will be for the better necessarily, but I view change as inevitable. The survivors will be the ones with the right game plan.
I plan to use the price scope, but need translation of the specs as written on the AGS report:
Round Brilliant cut, 7.80/7.88 x 3.46. 1.30 carats, #8 cut, #5 color, #3 clarity. what does 6.5 dwt. mean?
#5 color = IJ color
#3 clarity= VS1 clarity
#8 cut = Poor cut
The millimeter measurements you listed indicate a very shallow diamond (44.1% depth), which is the reason for the "poor" cut grade. Most well cut diamonds fall somewhere in the 58-62% depth neighborhood. This one is what dealers refer to as a "pancake" stone.
That's not to say that it's not pretty. It just doesn't line up with the traditional stats for a well cut diamond.
6.5 dwt= 6.5 pennyweights, or 10.1 grams (weight of entire ring)