I don't believe that 800-1000 calorie number, either. I'd guess that the 200-400 number is quite a bit more accurate.
100 calories per mile of running seems close to me. I'd believe 150, too, but it probably depends a lot on how much you weigh, how good you are at running and how fast you go.
The problem is that most of the accurate information we see about calories is how much we're eating when we eat packaged food. Having to run 2 miles to run off a can of pop seems ridiculous, but it's probably pretty accurate. It's a good illustration of how important diet is when you're trying to lose weight. It's easy to cut 500 calories out of a poor diet but takes a lot of work to burn an extra 500 calories by adding exercise.