I've been made a Lower offer than what's advertised

[Jordi60]

How do I accept a lower offer. And what percentage do Airbnb take ?

[Helga0]

If you are a host and a guest suggests a lower price by message, you can send a special offer at this price or another. The special offer includes all extra fees, but not the airbnb fee. So consider: you may have a night rate, an extra person’s fee and a cleaning fee. If you send a special offer, this price contains all that. From this price is deducted your usual airbnb service fee (probably 3 %) .

to this price is added the guest service fee, which may be any amount between 6 and 12%. No way to predict it, you have to try. 

Don’t let guests negotiate you down too low, it’s always a bad idea.

[Isabelle193]

If you send n offer make sure you add in your cleaning fee into the final total as the Airbnb App will not calculate it in 

it’s very misleading and I’d suggest you do your math carefully so as not to be out of pocket as I experienced myself recently as a Super host