How can I change my thick hair's wave on a tight budget?

I have thick, wavy, shoulder-length hair that doesn't cooperate! Specifically, it always flips outward really badly at the ends (looking like a different decade). I'd prefer it to go slightly inward. I haven't had much luck with my straightening iron, probably because I can't afford a really good one. What I have helps for a few hours, but by lunch time I'm ';flipping out'; again. I've thought about buying a curling iron or hot rollers, but I'm afraid of adding too much volume; I already have days when my hair is so thick that it looks like a bush! I'm also afraid of damaging my hair with too much daily heat (which is another reason I'm not crazy about the straightener). So... Any suggestions on achieving good results without spending a ridiculous amount of money?How can I change my thick hair's wave on a tight budget?
The best straightener out there is the chi. But its pricey. Maybe you could save up money for it. Also check out overstock.com. You can get some pretty good deals on them. In the meantime blow dry your hair straight. Just brush you hair while blow drying it and style it the way you want it.How can I change my thick hair's wave on a tight budget?
herbal essences dangerously stright
I use Sleek Look Shampoo/Conditioner by Matrix. It really helps with controlling your hair and also makes your work with the straightening iron/blow dryer last longer. They also have some lite leave in straightener that works great.