Commercially produced First Day Covers of standard commemoratives like the LBJ stamp are typically worth a dollar or two. They can be purchased for on eBay or through dealers. Higher value stamps, or specific cachet makers are worth more. A specialized catalog will list the value of a cachet or un-cacheted cover.
Scott number 1503 has a catalog value of 40 cents in mint condition.
1.00
What is the value of a boston tea party bicentennial 8 cent stamp worth
The value of the Robinson Jeffers 8 cent stamp is around $1.50 in unused condition and around $0.20 in used condition.
About 25 cents
VALUE
40 cents
You will need to more clearly identify the stamp to determine the value. There are a number of variations. In general, they will have minimal value. Consult a stamp catalog to identify it.
5 cent
Mint: 8¢. Unless it's a rare variety, its worth approximately 1¢ used, sadly.
8 cents.
8 cents.