The cost would obviously depend on your day rate and how many bookings you have.
There are two options for host fees https://www.airbnb.co.uk/help/article/1857/airbnb-service-fees
What do you mean by pros and cons do you mean using Airbnb as opposed to other platforms. If so have a look at some of the other platforms that operate in your area and you can see how they work,.
The main advantage of using Airbnb is they are the biggest STR listing operator and invest heavily in marketing.