That's not what a broker does. A broker is basically in sales. He takes company research done by analysts and tries to sell you company financial products. He doesn't care which direction you go as long as you do something so he can take his commission, and a little extra if you are buying a company product he might be trying to push.
A market maker is the guy who's tying to capture the spread, but they don't really go around trying to get the public to buy and sell.
Not sure if the answer is obvious here but I don't know much about finance, does 'spread' here mean the difference in the asset price from purchase/sale time (whether by market change or artificial markup) or the brokering fees involved? or both?
Any vendor will buy a good at say, $9 and sell at $10. In the US there are many pawn shops saying "We buy and sell gold!" - it's never at the same price.
#1: A smart gold trader will buy low, sell high.. they will buy more gold when prices are low and advertise to sell more when the price is high.
If they're selling pure gold at less than or equal to $800/oz then it's well worth it at this very moment with gold trading around $1200/oz right now. 50% profit ain't shabby.