Could i buy something with a Silver American Eagle Coin?

American Eagle coins are bullion coins, which means they are not intended for use as circulating currency and have no fixed value. Their value is determined by the current price of the metal they contain (in this case, silver). As a non-circulating coin, no one is obliged to accept the American Eagle as legal tender, which is the case for coin or paper currency. However, the bullion coins are very valuable and it is quite possible to arrange a barter transaction with American Eagles so long as you can find a supplier willing to trade something for them. So yes, you could "buy" something with a Silver American Eagle, but the transaction will be much more complicated than purchasing with ordinary currency. For one thing, you could sell your Eagles for cash! There are many traders willing to make that transaction.