How much is a 1988 madero 500 worth
Estados Unidos Mexicanos (United Mexican States) is the official registered named of what is commonly known as México, just as we might call United States of America, the States or USA or America. Geographically we are located in North America. Juan De La Torre
Most Mexican currency is made of nickel and copper alloys, but there are gold and silver coins called Centenarios and Onzas Libertad, respectively.
It means it has 5 oz of silver, valued at some 89.65 dollars. The motif of the coin could add some value, though.
It is .100 fine silver, it's nick name in Spanish, Feo means ugly do to it's low content and the fact they turn a ugly (rusty) gray and black.
You are asking about a coin from Mexico ("ESTADOS UNIDOS MEXICANOS" is Spanish for the "United Mexican States", Mexico's official name) dated 1993, but you would need to know the denomination and condition to value it. Denominations of 5, 10, 20 and 50 Centavos, and 1, 2, 5, 10, 20 and 50 Pesos were produced in 1993. None of the centavo coins are worth more than a dollar or so even in uncirculated condition, although the 1, 2, and 5 peso coins may be worth a couple of dollars even in Extremely Fine (that is, slightly circulated) condition. The 10, 20, and 50 Peso coins are bi-metallic, with silver in the center, so they will have value as silver separate and apart from the numismatic or exchange value.
Your coin is made of stainless steel rather than silver. I'm afraid I have to inform you that you have an ordinary circulation coin. The Mexican peso is worth about 10¢ U.S. and there are 100 centavos in a peso, so a 10-centavo coin is only worth one U.S. penny.
A .20 estados unidos mexicano coin is worth about, well, nothing. If you have five of them, you could buy a piece of gum.
Assuming that you are referring to the commonly circulated 1987 100 peso coin (made of aluminum bronze - it sort of looks like brass), it is worth about US$0.60 in nice circulated condition and about US$3.00 in Brilliant Uncirculated condition. If you are referring to the 72% silver 100 peso coin issued to commemorate the World Wildlife Federation (with Monarch Butterflies on the back), it is worth about US$50.00 in Proof condition, and has about 0.75 troy ounces of silver (which has a melt value of around US$10 as of the end of February 2009).
Several factors have to be considered. First is the date because the percentage of silver changed from 90% over time down to 10%. Second would be the mint mark. Third would be the denomination, 500 what?Take it to a collector or dealer (careful, some dealers will tell you it's only worth scrap prices) Not so!Fourth is "Condition!" Condition decides if it is a $1 coin or a $1000 coin!
You are asking about a One Peso coin from Mexico (KM#459). The coin is 34.5mm in diameter, weighs 16 grams, and is 10% silver, giving it an ASW (Actual Silver Weight) of 0.514 troy ounces). The front has a portrait of a man facing right within a wreath. The back has an eagle with a snake in its mouth within a wreath, with "ESTADOS UNIDOS MEXICANOS" (Spanish for the "United Mexican States") above and "UN PESO 1960" ("One Peso 1960") below. The edge reads "INDEPENDENCIA Y LIBERTAD" ("Independence and Liberty"). 26,259,000 such coins were produced in 1960 at the Mexico City mint. With silver at US$33.80 per troy ounce (as of July 1, 2011), the "melt" value of the coin is about US$1.74. According to the Standard Catalog of World Coins, the coin is only worth its silver value in circulated condition - in Uncirculated it is valued at US$3.25, and in Brilliant Uncirculated, US$4.50.
A mint condition uncirculated 1959 100 Peso note is worth $25, dropping to $2 for a crisp circulated one in Very Good condition.