3 or 4 enquires a month in the summer maybe 1 a month in winter. And I rank pretty well.
95% of my work comes from Facebook.
What do you do just sponsor the ad?.
How much money do you need to put into Facebook to get enquiries and how much do they charge you per lead
I don't have much experience with Facebook, as I mainly do Google Ads, but I know that Facebook won't charge you per lead, because they charge per CLICK, pretty much like any other advertising platform.
This means that every time your ad gets clicked, you will be charged - whether that click results in a call or a sale, it doesn't matter, as Facebook sells you advertising space, NOT leads.
The reason why I prefer Google Ads, instead of Facebook, is because it allows you to target visitors by keywords, so assuming you select the right keywords with good commercial intent, then naturally your conversion rates will be higher, as more people will call/buy, etc.