Here is something kind of exciting. You don't need a popcorn popper to have healthy popcorn! You can put a 1/3 cup of popcorn kernels in a small, brown paper lunch bag folded over at the top and cook it in the microwave on the popcorn setting.
If you don't have a popcorn setting you wait until there are two seconds between pops and memorize how long that took for next time. It is super easy with no butter or salt. I personally think it is still pretty tasty but I don't like the butter and salt on it anyway.
The bags can actually be reused if you are into that sort of thing or you can buy them for pennies at the grocery store. I think this is the secret that microwave popcorn makers have been hiding from us for years!