From a coin shop, Ebay, flea markets, coin collectors, advertisements in coin publications.
No you can buy coins or you can buy a upgrade card for 5,000 dragon coins
You can't buy coins in heartgold or soulsilver.
Yes, they do buy and sell coins and stamps.
Banks don't buy old coins, coin dealers will buy old coins, some jewelry stores will buy old coins, banks will take your old coins at face value and then sell them to coin dealers and and make some profit.
You can buy Pokemon, though not with the money you buy stuff like potions with. In Goldenrod city and Celadon city there is a game corner, you play a coin game called Voltorb Flip and earn coins. You can buy Pokemon with the coins too. In Goldenrod, you can buy an Abra (200 coins), an Ekans [HeartGold] or a Sandshrew [SoulSilver] (700 coins) and a Dratini (2100 coins). At Celadon, you can buy a Mr. Mime (3333 coins), an Eevee (6666 coins) and a Porygon (9999 coins).
No, banks do not buy old coins. However, there are a lot of coin dealers and jewelry stores that will buy old coins. There are also private collectors of older coins who will purchase them too.
Go on the catching waves upgrades at the cove and click on the w in waves and its 800 coins to buy
You grow easy crops to get coins or you buy the crops that take a long time to come in because they are worth alot of coins or you can buy coins for farmville
Coins on clubpenguin are money. You need coins to buy things.
You have to buy them, I think why not play and have fun then buy digital money(e-coins)
You need to buy Moshi Coins.
Coin collectors will buy your coins.