Treadmills???

Hi there. Hoping for some enlightenment, I would like to buy a treadmill. Please can people recommend any? I have spent ages looking but they either seem to be hideously expensive or rickety and cheap. Budget is £500 but hoping it may come in cheaper. I am not a big distance runner now but would use it 3-4 times a week to help me lose weight and regain some fitness.

Has fingers crossed for some inspiration...