Chemically straightned hair?

I want to get my hair chemically straightend I have curly poofly hair and it dosnt stay striaght I have a chi straightner and my hair poofs up right after I straighten it whether its hot cold or perfect temp outside it takes about 35 or so minutes to straighten anyways I want to get it chemically straightened I was thinking about a home kit but I'm not sure which one is good or ill go to the salon but I don't want to spend more than 100 or 150 if possible any suggestions? Has anyone had this done? What was the outcome? Any advice would be helpful thanks :)