Recently I entered a discussion with someone that has a relatively popular YouTube channel which says among other things that the earth is flat. I said that earth isn't flat because you can see the ISS by yourself through the telescope. I was reminded that I'd only seen it on the internet, but not actually seen it directly myself. I was told that if I buy a telescope and film by myself they will also buy one, do the experiment, and post the footage on their YouTube channel.
So, what's the cheapest telescope that I can buy and record with a cellphone? I've seen people using a Nikon P9000 but what matters is its lens, which is already expensive, and the camera is expensive too. Maybe it's possible to buy a cheap photography lens that has both good quality and high zoom and can be used with a cellphone?