Editor for a non profit magazine

We are a non-profit organization with a monthly newsletter magazine. We currently have an editor but contract is almost up and bidding the job out. The magazine is currently (6) 11x17 pages that makes up a 24 page newsletter/magazine. We use 8 colored pages and the rest are black and white. Certain criteria is used on the colored pages. All inside content is submitted by members of the organization by the 15th of month to be sent to our printer by the 20th. There is a template that is used for page content, but looking to change the magazine template layout in coming months. Please give a quote on editing.