The mine in the Hay Day game will be unlocked to the player once the twenty-fourth level of the game is reached. In order to be able to repair it you must have at your disposal 26.000 coins to spend and the wait for the process to be completed.
After a while and once the process have been completed you will be able to use the mine to retrieve valuable items such as diamonds, platinum ore, gold ore and silver ore. All of this highly valuable material can be either sold or used at the jeweler building to make items that will give you much more money if you sell them.
Something to notice is that unlike some other resource production buildings; you will require tnt, dynamite and shovels so when you blast away at the structure you earn a random item. So actually, sort of the only real use for the mine is to get the previously named items, those will make you earn a lot of coins and experience for real once they have been produced.
Never the less, you should consider the amount to invest, because it is no game. Once you reach level 24, take a look at your financial state and plan ahead, but of course there is no need to say that it is not completely essential at all to go down the Hay Day’s mine road.
All right then, so far you know how to keep animals fed and how to begin to produce some goods. But that is not enough, because in order to keep things running you need to sell stuffs. There are a few ways to get this done. In the first place some people can simply visit your farm and ask for specific things, if you have it, you can provide them with it and make some profit in the meantime.