I've never heard of them either. You can usually find free or cheap used treadmills online, it's the kind of investment most people don't make use of. I highly recommend going this route, it's worth the hassle.
When I got a new one this year i had my old one and my wife's old one still and I couldn't get anyone to take them for free even. One of them ended up going for scrap but the other one I just finally found a home for.