Can anyone tell me about the complete functioned models of cell phones in an affordab

Hi everyone, I am a marketing agent and unremitting user of cell phone because of my job work. But, actually I want a cell phone with all the necessary functions in it and also affordable to me and must be in my budget. Can anyone tell me about such cell phone models which will be available with all required functions and in an affordable financial plan? I really want one of such cell phones. Any help is appreciated.