For Morgan dollars, Carson-City mintmarked coins are common, but some dates are considered scarce and some are rare in the higher grades. But no, not all CC Morgens are rare.
No circulated bicentennial dollars are rare. If it's a silver proof, it will weigh more than a regular Eisenhower dollar, and it will have the mint mark S.
W is the designer's initial (A. A. Weinman). The mint mark location is on the back at roughly the 8:00 position - blank, D, or S. Regardless of mint mark, 1943 is not a rare date for half dollars. As of 01/2009 it's worth $6 - $8 for its silver content.
You could get around $30 for a common date in circulated condition. If it is a rare date and uncirculated you could get thousands of dollars but that is unlikely. They have a silver melt value of around $26. For a specific value, ask about a specific coin (with date and mint mark).
Most silver dollars are worth 15-20 dollars. Certain rare mint marks can increase the value. And, of course, condition is very important.
1957 is not a rare date for Washington quarters. Its value is based on the silver it contains -- as of 12/2008, about $2.50
War Nickel, or silver nickels started in 1942 through 1945. 1942 produced both nickels out of nickel and nickels from silver. The non silver ones do not have the large mint mark while the silver ones have the large mint mark.
Franklin half dollars are not rare or even scarce, if the coin has any wear at all value is just for the silver about $12.00.
There are several so-called "key" dates: 1879 CC 1884 S 1889 CC 1892 S 1895 no mint mark, proof. Prices can range up to a half-million dollars for superb uncirculated specimens.
All Franklin half dollars are 90% silver with a current melt value of around $12. 1958 isn't a rare date, so in mint condition, it's only worth a couple dollars more.
It depends on the year and condition. Common or well worn coins are only worth their silver content, which would be around $26 at current market prices. Coins in better condition are worth more, as are those with a more rare date or mint mark.
If your coin does not have a mint mark then it means it was minted at the Philadelphia mint. These coins are usually not as rare. However recently P mint marks were added to coins to indicate that they were made at the Philadelphia mint.
1941 is not a rare date for Walking Liberty Half Dollars. In average condition its value is determined mostly by the coin's 90% silver content. The price of silver changes every day, so check a newspaper or financial site for the current price, then multiply by 0.36 for a rough retail value. A dealer will pay half to 2/3 of that amount.If your coin is in better condition, check on the back near the 8:00 position to see if it has a mint mark. Numismedia lists the following approximate retail values as of 02/2011:No mint mark (Philadelphia):Almost no wear - $25Uncirculated - $32 to $5,430 depending on quality"D" mint mark (Denver):Almost no wear - $30Uncirculated - $37 to $940"S" mint mark (San Francisco):Almost no wear - $53Uncirculated - $77 to $18,530Answerfrom 7 to 30 dollars depending on condition and mint mark. 7 dollars in good condition, 7.25 dollars in very good condition, 7.50 dollars in fine condition, 8 dollars in very fine condition, 9 dollars in extremely fine condition, 13 dollars in about uncirculated condition, 35 dollars in uncirculated condition, 50 dollars in high grade uncirculated condition, and 850 dollars proof.