There are two reasons to need a broker

1. Buying gold for an IRA. You can do a self directed IRA, but in so doing, you cannot really touch the money (or else). So you need a group that buys the gold for you. There are a couple good ones.
2. Buying gold to be vaulted in another country. There are also several of these. And if you have a lot of money/gold, having some of it out of the country is a good play. Of course, you may lose that gold because of the company or the country claiming your gold... but it is a hedge against The US doing the same.

Anyone else, walk into your nearest coin shop and buy the shitz.