I cannot tell you what to charge. You will have to check around your area. I charge the same rate for events as for overnight stays, and I do not change rates for weekends. My only increases are for the week of our local county fair and for the Christmas holidays. I find that keeping the rate the same keeps everything transparent for guests because I have repeat guests and they know what renting my listing will cost them.
I guess that about 20% of my events guests are booked through Airbnb....the rest come from me visiting churches, funeral homes, curling rinks, ice skating rinks, our local gym and all the restaurants in my area. They all have my business cards. That is where the best bookings come from. I am in a small community and I feel more secure renting to local people because here in my community people still want to keep their "good name".....if you know what I mean.