Yeah it's not terrible, but having 10 extra pounds of muscle burning almost 100 calories a day extra, thats like a pound of fat every month and a bit.

And that is the same amount as having 10 extra pounds of fat burns.

1kg of muscle tissue burns pretty much identical amount of calories as 1kg of fat tissue. Heart, kidneys, brain etc. tissues burn more than muscles/fat, but you can't really grow those.

Xkg person's basic energy burn rate is the same, regardless of his fat percentage.

Therefore it is definitely a myth to promote weightlifting on the merits of muscles being some kind of great energy expenditure machine.

That's assuming the extra calorie burn doesn't make you feel hungrier and cause you to eat more, even if only a little. 100 calories is a very small amount of extra food.