Remember, it's a proven fact that most people lose money trading commodities. And the reason is NOT the cost of commissions. It's because they put on losing trades. Full-service professional advice is available for a small additional cost, and can be worth many times the price. The next time you see an ad for a discount brokerage company, ask yourself why they are telling you how cheap they are.
People advertise quality when they have it to offer.
Otherwise they can only sell you a cheap price.