How much money would I make from a Facebook page with 100,000 likes?

Depends on what niche it is and what type of audience you have.

If your page was about home mortgage tips for people in California then you could do 3–4 advertised posts per week for home lending companies. Lets assume they would pay $500 per post, so it would total to $2,000 per week or $8,000 per month.

On the other hand if your page was about funny posts and your audience was comprised of third world countries, then I would surprised if you can make $10 a month from it.

*Remember this is all assumptions based on previous pages I worked with*

The amount of money you make depends purely on who your audience and how much advertisers would pay to get a post to them.

The best way to gauge what the value is, is by creating a Facebook campaign of your exact audience and check the FB CPM for it.

I highly suggest you check out The Campaign Maker it automates your Facebook ad creation process which can lower your Facebook ad costs by up to 20% within 14 days, best of all it has a free 14 day trial to test it out.