I wish to ask AVVO what would be a reasonable amount of time spend by an attorney for a Demand Letter?

A Demand Letter for a tenant/landlord problem, and a reply from the attorney for reading the landlord's response. Once again, I only wish to have an estimate and/or average for a sensible amount of time spent on this.

Details: I provided pictures of the landlord's violation, such as unleash dogs (unlawful) and I printed the animal control's law; the U.S. Post Office Federal Title for unlawfully placing documents in mailbox (with examples);pictures of the landlord's violations of his own rules and regulations in apartment complex. I performed the majority of the research and provided the evidence to the attorney at the initial consultation.

Therefore, I only desire to know what is sensible amount of time on this?

Thank you for your response.