How to buy gold – gold dollar versus gold?

Hello, I have an interest to buy gold. However, I am very confused by the different gold coins (American Eagle, American bison) and the gold dollar. Can someone please distribution differences for me? More precisely, is the value of gold as the dollar Gold 2002 (Denver Mint Mark A23) Gold? Why an American eagle cost so much? Thanks

American Eagle because it costs more symbolizes peace and war for America.

The Silver Eagle Dollar

1927 $2 1/2 DOLLAR INDIAN HEAD QUARTER EAGLE GOLD COIN LOW MINTAGE $399.99

1885-S GOLD $10 * NGC MS62 * LIBERTY HEAD EAGLE * $1,415+++ Ten Dollar $945.00

USA 5 DOLLARS GOLD EAGLE COIN DOLLAR 1899 XF++ $549.99

★ TEN ★ 1849 $20 LIBERTY DOUBLE EAGLE ★ GOLD TWENTY DOLLAR COPY ★ PROOF COINS ★ $24.95

1- AIR-TITE COIN TUBE-TITE HOLDER- Dollar/Silver Eagle/Bullion Rounds/Gold-2″dia $1.79

1889-S GOLD $10 * NGC MS63 * LIBERTY HEAD EAGLE * $2,000++++ Choice + Ten Dollar $1,276.00

1857-O LIBERTY-HEAD GOLD $2½ DOLLAR QUARTER EAGLE AU $869.99

Uncirculated 10 dollar gold American Eagle. $460.00

1909 GOLD * PCGS MS64 * INDIAN HEAD Quarter EAGLE * $2 1/2 Dollar Choice $3,250+ $2,025.00

1910 INDIAN Head UNITED STATES Gold $10 TEN DOLLAR EAGLE COIN High Grade $900.00

2001 One Tenth Ounce, Five Dollar Gold Eagle Proof and packaging $201.00

2001 One Ounce American Gold Eagle 50 Dollar Coin $1,773.98

1933 US Gold Double Eagle 20 Dollar Reproduction Proof Copy Coin FREE USA Mail $42.00

Replica 1798 Turban Head Plain Eagle $5 Gold Dollars $2.99

Replica 1798 Turban Head Eagle And Shield $5 Gold Dollars $2.99