I want to buy the Mining Helmet from the Merchant, but it costs 8 Gold Coins, and I do not have any. How do I get Gold Coins?
1 Gold Coin is simply 100 Silver Coins. They're automatically created when you pick up 100 Silver Coins, but they can also be manually crafted.
If you're looking for good ways to farm coins, have a look at this question.
One of the quickest ways to rake in the coins is farming meteor heads. You'll need to break a single shadow orb to spawn the meteor. Shadow orb harvesting is hard but you can do it much earlier with clever tunneling and a couple sticks of dynamite.
For continued quick coins an artificial meteorite biome can be used instead.
I find that blood moons are excellent opportunities for making some money. Build upwards into a hill and simply stay there and let the zombies climb up to you whereby you can hit them back down until they're (un)dead. It should be upwards because too many zombies on a flat surface during blood moons can overpower you despite swinging your sword non-stop.
Similarly, goblin armies are useful for making money (albeit perhaps a bit later in the game).
However you can also follow the safer routes mentioned in the wiki. I would strongly advise you to invest in a piggy bank where you should store your coins so that you don't lose half during a battle. It costs 1 gold coin though.
You can sell precious stones (amethysts, rubies, etc). They sell for a good amount of money and don't currently have a lot of uses. If you want to make a phase blade or jungle armor later in the game, make sure to set aside what you need for those first. Note that you also risk missing out on any other uses for them that could be added in future updates.
An easy way after you've gone into the Dungeon and got the Mechanic (or otherwise have a friend capable of wiring) is to do the following:
- Put a Goldfish statue (or several) at the bottom of a 2 x n pit
- Add a hostile mob statue about 10 blocks above it off to the side, in its own 3x2 hole -- I prefer crab statues but any will work
- Wire them up to a 1-second timer and stand underneath the fish spawner
- Optional: Add in a Dart Trap or two to take care of Blood Moons.
You can effectively stand underneath the spawner and farm Goldfish as long as you want. If you throw in a Heart statue where you're standing, you'll probably never die if you're above ground. Just return every hour or so, sell off your piles of goldfish, and rake in a ton of gold per trip.
Blood Moons become even more profitable because the fish will immediately turn into Corrupt Goldfish, which drop plenty of money, no sales trip needed. (You will have to add the dart trap, though. Otherwise, well...)
This isn't the most effective method (by far), but it's something you can pretty much set-and-forget for an hour at a time, no further interaction necessary.
If you're needing a mining helmet then this probably isn't going to be applicable for you, but the dungeon is a great way to make cash. So many things spawn there that you keep raking in cash drops as you kill. By the point you get there though, you probably aren't worried about just 8 gold. I figured I would toss this answer in since people may want gold for other things than a mining helmet. I believe I made my early money just mining a bunch and selling off gems. I never bothered with the mining helmet personally, I just used torches until I found an orb of light.
I've found the best early(ish) way to make money is to farm the Eater of Worlds, he drops over 99 Demonite per encounter, which sells for rougly 8 gold a stack. If you use a Vilethorn he's extremely easy to kill repeatedly. The only part about this is getting enough vile powder to repeatedly summon him, but such powder can be bought from the dryad during a blood moon at the price of 1 silver per powder. IE: 30 silver per summon, with each summoning gaining you almost 8 gold. So it easily pays for itself if you drop 3-5 gold into vile powder. Between that and a mediocre Vile Mushroom farm you should be fine. The EoW drops enough rotten meat himself to supply that half of the crafting reqs for the Worm Food to summon him.
You can get money from:
- killing monsters. You need a lot of monsters. So it is good idea to make hunting when blood moon arises. Or you can try to summon goblin army :-) if you dare to kill them.
- crafting and selling items. It is very easy to craft bottles from sand, torches from wood and gel. They costs not a lot, but you can craft a lot of items :-) Also I want point that you will need to work hardly. Because 1 gold coin is equal to 100 silver coins or 10000 copper coins. And prices for torches and bottles are 10 and 4 copper coins resp. You can see how much items you will need to sell :-)
1) Kill stuff
2) Get better equipment (gold, meteroite, demonite)
3) Kill stuff faster
4) Google +Terraria +Mob Grinder
5) Kill stuff even faster
6) Make use of fast time, i.e. turn frame skip off, minimize terraria by clickin on its icon in the taskbar, not the minimize icon in the window
7) Kill stuff ultra fast and get rich in no time