Does a 1943 wheat penny with no mint mark have any significant collector value?

Short Answer

In circulated condition it's worth about 5 cents ... A nice uncirculated one is worth about $1.00

Answer

Lots of coins have no mint mark. Specifically, all cents made at Philadelphia, even current-date cents, are "plain"; that is, they do not have a mint mark below the date.

Mintmarks

With the exception of a brief period in 1838 and 1839, all U.S. branch mint coins before 1909 displayed mintmarks of their place of manufacture on the reverse. Larger denominations of gold and silver coins were labeled with the Dahlonega, Charlotte, and New Orleans mintmarks on the obverse (just above the dates) in those two years. Carson City served as a U.S. branch mint from 1870 to 1893, producing coins with a "CC" mintmark.

In 1909, the introduction of the Lincoln head cent first saw the mintmarks moved to the obverse of American coinage. Between 1965 and 1967, American coins featured no mintmarks of any kind, in order to discourage the hoarding of coins. Mintmarks were moved to the obverse of the nickel, dime, quarter, and half dollar in 1968, and have appeared on the obverse of the dollar coin since its re-introduction in 1971.

On the nickel, the mintmark is currently located near the rim clockwise from the date. Dimes have their mintmarks above the date, while quarters have a mintmark to the right of Washington's bust. The half dollar has a mint mark just to the right of Kennedy's bust, and the Sacagawea dollar's mint mark is just below the date.

Philadelphia coins (produced at the site of the main U.S. mint) featured no mintmarks until 1942. Midway through the year, the composition of the nickel was changed and the mint mark relocated from the right edge of Monticello to the large space above its dome. For the first time, Philadelphia-struck coins bore a "P" mintmark, which continued through the end of 1945.

The "P" mintmark was discontinued after the war, only to reappear in 1979 on the Anthony dollar. By 1980, it had appeared on every other regular-issue coin except the cent, which still bears no "P" mintmark. The cents previously minted at San Francisco (except proofs) and West Point also bear no mintmark, as their facilities were used to supplement Philadelphia's production.

See the Related Link "Wikipedia: United States Mint" for more information.

Y-THINK-Y

And don't forget if it won't stick to a magnet then it's worth $10,000 or more.!