Build or make some changes in a plethora of websites - long term

I am looking for a web developer with hands on experience in HTML, CSS, PHP and MySQL (languages needed for developing basic websites). I will regularly give the projects ranging from 500 INR to 2000 INR but the count of the projects would be around 100. This will go on for a long term so that person has to stick and always work for the little changes or major changes as well. Projects could either involve changing the design or functionality or even developing from scratch so kindly bid only if are available to work on many projects in specific budget and time.