Craigslist Autoposter

I would like to develop a program or script that can post ads on craigslist in certain categories. I don't want to overpost to get flagged, but I want to automate the process if possible. I would think that if I had a database of different ad versions and different email addresses, that we could use this database to post the ads within control. Like posting 1 add in each desired category in each desired city per day, and deleting that ad the next day and posting a new one. In your bid, give cost to develop this script/program, how long to develop, what your plan is, or if you already have this program to sell me a license.