How much does Facebook advertising cost?

The honest answer has two layers. Layer one: you set the budget, so Facebook costs whatever you decide daily, and modest daily amounts are enough to start and learn. Layer two, the one that matters: what you pay per LEAD depends on your industry, your audience, your offer, and, biggest of all, the skill behind the campaign. The same budget in skilled hands can produce several times the leads of a beginner's setup, same platform, same money, wildly different results. That skill gap is exactly what you are buying with a managed campaign: not access to Facebook, which anyone has, but years of knowing what pulls response. Budget for at least a month of consistent running before judging anything. One-week tests only prove impatience.