Which shows you can cook a lot of the fat out of 70/30 ground beef. However, there's a serious flaw on that site: they imply that there's less fat in the 70/30 after cooking than in the 93/7 after cooking.
After cooking, the superlean contains 680 calories in 12 2/3 ounces of cooked meat.
The 70/30 contains only 620 calories, but in only 11 ounces of cooked meat.
Superlean: 53.68 calories per ounce after cooking
70/30: 56.36 calories per ounce after cooking
Certainly, this shows that the 70/30 is usually more economical (around here, the super lean is nearly double the price of the 70/30.) The flaw in the argument is more obvious if we consider it this way: if I could cook 100/0 (0% fat) ground beef, then after I cook 1 pound of it, I'm going to have a LOT more remaining calories than if I cooked 50% fat (the OP's meat

) and remove as much of the fat as possible (but 100% fat removal after cooking probably could never be achieved.) Also, why doesn't the person who wrote that article attempt to drain away as much fat as possible from the 93/7?
Although a portion of ground beef is usually based on 4 ounces of raw meat, that's based on a rough estimate of how much you're going to have after cooking. I could of course, prepare hamburg that's 99% fat and 1% meat. It'd be the ridiculous extreme to claim that after draining away all the grease, my 4 ounces of raw hamburg now has only 20 calories after cooking.