Just about all collectors of US coins enjoy the famous 'buffalo nickel' of 1913 to 1938. The design of this coin is amazing. There is observable dignity and strength in the portrait of the Native America, and the buffalo (or bison) on the back is unparalleled in modern coin design.
The same Indian/buffalo design has been used in modern times on breath-taking gold bullion coinage. Most of these gold coins are really dazzling. They come in various sizes:
$5: 0.10 troy ounces gold
$10: 0.25 ounces gold
$25: 0.50 ounces gold
$50: 1.00 ounces gold
You can find them in proof versions, uncirculated, burnished, first strike, and other variations. They also come with fancy packaging. The variations and packaging do not affect value very much.
All gold buffalos are worth, at a minimum, the value of the gold they contain. To find this base value, or BV, multiply the current price of gold by the content. If, for instance, gold is selling at $1200 US dollars per troy ounce, a $25 gold buffalo contains BV = 0.50 x 1200 = $600 worth of gold. Look up the current value of gold at kitco.com.
As a general rule, these coins sell retail for about 10 percent over BV. If you can find one in a numismatic slab by PCGS, NGC, ANACS, or ICG, the retail price rises to 20 percent over BV. For instance, with gold at $1200 per ounce, a $25 coin would sell to a collector for about 0.50 x (1.1) x 1200 = $660 and, if it were slabbed by PCGS, for about 0.50 x (1.2) x 1200 = $720.
Wholesale pricing is different. If you have a coin to sell and want to sell it to a coin dealer, the dealer must make a profit when the coin is sold at retail. Figure about 10 percent below BV for a coin sold to a dealer.