It is normally the policy of this helpdesk not to do assignments for students but I will give you some hints on where to get pricing. You do not say where you are and if this estimate is also to include labor costs. If labor is to be included, use the rate in your area for either a telecommunications tech or an electrican. As far as the equipment goes the web is a great place to get pricing directly from distributors and retail stores. Try looking up your prices at Radio Shack, Home Depot or even some of the advertisers here on this web site. Also check out ebay if you can't find everything.
Your cost breakdown should include a materials list (cable, connectors, camera, monitor, etc) including any infrastructure required (conduit to protect run outside?) Then put together a labor estimate by listing all the tasks: running cable; terminating; testing; mounting equipment, system test, etc. and multiply the total hours times the labor rate researched.
Joseph Golan, RCDD