Wanting to have treadmill

I have keep checking a treadmill online ever since before, however I just couldn't find any cheaper ones that fits on my budget. I already look at the forums in our local area where people can sell used stuff for cheaper price but i haven't had any luck. One of my friend says i have to checked often since many people are wanting to buy them. I just don't know when i be able to have one. I am pretty much excited on using treadmill on my daily exercise.