Help In Saint Gauden $20 1924

Here is a value list http://www.numismedia.com/rarecoinp...proof=&plus=
John1

I have an example of the same date. This example slightly better than mine.
Grade?
I agree with Coinfrog. re grade and authenticity.
If you have any doubts about authenticity, carefully check for accurate weight. If still unsure, get an XRF test for 900 cold /copper in the alloy only.

Comparative ping tone test can be carried out by tipping the edge gently with another coin, and comparing the ring against a known genuine coin. Should be done over a soft surface such as a blanket, lest the coin fall. This will prove if it has a tungsten core. Tungsten has same density as gold, and will give the same weight, but will give a very dull ring.

As per edge pictures, small bumps let it down a bit, but still a pleasing coin.

I have 16 examples in my collection of this coin in various dates from 1907-1928, and I don't see anything that leads me to believe your example is fake. 1924 is the most common date (followed by 1928 and 1908NM). In other words, if someone was planning to counterfeit a Saint using real gold, counterfeiting the most common date would make little sense as there is unlikely much numismatic value beyond gold melt value.

As others have said, weight, diameter measurement, ring and (if you have the capability) spectroscopy are ways to better assure yourself of authenticity.