I agree with @Rebecca look at what other local hosts are charging for comparable listings .
you also need to do a profit and loss account to identify your one off and ongoing costs so you can estimate likely profitability at the price point you are charging based on how many days you estimate you are likely to be booked and at what price.
What a great question - it must be hard to know where to start. From previous threads here on the Community Center, a lot of hosts have found it useful to look at similar properties in your area. Have you checked what others are charging for comparable listings?
I agree with @Rebecca look at what other local hosts are charging for comparable listings .
you also need to do a profit and loss account to identify your one off and ongoing costs so you can estimate likely profitability at the price point you are charging based on how many days you estimate you are likely to be booked and at what price.