Gold is a product that's been on the market for a long time so there isn't a lot of empty space for a refiner to come into and just start working. You will compete with anyone else already established in the market. That said, it can be done and with a good eye for opportunities it might work. But to compete you need knowledge, skill, access to chemicals, access to raw material, a place to sell the product or to make it into a saleable product, various permits depending on where you live, a place to work and store material... and so on.
We can help with knowledge, just study the forum. Skill you have to earn. I spent a year before I dissolved any gold, first time refining worked perfectly but the second time I ran into problem. Every time you refine something you get better on refining, failures as well as successes.
If you are serious about learning the trade then making a loss now and then isn't a big problem if you learn something in the process, so buying at loss might be a good deal in the end.
Toll refining is a way to start small, but if you don't know what you are doing then you could easily find yourself in a bad place. That's something we have seen a number of times here at the forum over the years. It starts well, but too much work, too crappy material or a mistake and you lose the gold somehow (beaker breaks...) and you could easily find yourself in the red.
Easiest material to work with is carat gold but the margins are really low. You will compete with larger refineries that charges as little as 1/2% in larger lots.
Easiest material to find is old electronics but that contains very little gold so it takes a lot of manual labor to process. Here you will compete with companies buying boards and just sending it off for refining, getting paid on content. Batch sizes are usually 20 tons minimum. It ends up in a copper smelter so they have very little labor to pay for.
In the end, it depends on your proficiency in refining and your circumstances if you can make a living out of it.
Göran