While the adage in the title obviously doesn’t hold for farming it does hold for crafting and flipping. There is no getting around the fact that you have to spend gold to make it.
You make your gold when you buy
This is the main thing you should get out of this post. The way you make gold is to buy items that are too cheap. Then when you sell them at a reasonable price you can make a profit. For crafting there is of course some processing in between, but the basic concept remains the same.
Spending to decrease supply
Some markets actually require you to continuously shop to work well. Material flipping is one such, where it gets better the more often you can run a shopping scan. Every time you buy up to your maximum you take cheap items off the AH and replace them with slightly less cheap items posted by yourself. This increase the chance tremendously that one of your auctions will be the one to sell.
Buy low, sell normal
This was coined by an old gold blogger, I think it was Just my Two Copper, but I’m not sure. It’s another way to look at what you are doing when you are flipping and what you want to do when you turn materials into finished items. Buy when it’s cheap, sell useful stuff at a reasonable price.
Learn to love spending
As you need to buy items to make gold you should try to learn to love spending your gold. If the deal is good, then any amount of gold can be spent with a clear conscience. When I look at my weekly gold spent on BoEs I’ll see if I had a down week in terms of spending and then I’ll go crazy the next week. To get comfortable spending larger amounts of gold I have some tips in episode 23 of my podcast.