I would buy a used Pro Form in a 500 series or above. They are great machines and can be checked out at Sears. These treadmills go for $500 and up and you can find them for about $250 used. You have to get the tadin times or whatever they call it where you live(paper sold at Convenient stores with cars, bedroom sets, etc in it) when it first comes out. I found one last year and love it. The ones that go for less than $500 have a thin rubber belt(running surface) that streches and loosens . Good Luck.