It all comes down to what the page is about.
How much does it cost to target, say 1% of your Facebook fan-base on TV, or Google ads? Think about that, and then think about how often the people will be receptive to your advertisements - that's how you can work backwards to it's value to someone willing to pay for the page or run a 'promoted post.'
Your audience seems to be overwhelmingly 18-24 year old females in 1st world countries. Having 2.4 million people of this niche reacting to a post with say an engagement ratio of 1% - that's 240,000 people. Now, if the page is about little bunnies eating carrots, your niche is probably bunny owners, and won't respond well to a mascara product. If it targets make-up or some sort of fashion, then you've probably got a better chance of selling it for a higher amount.
