Personally, I'd rather just spend $20 on a Whirley-Pop and make it on the stove when needed instead of buying a machine. The popcorn turns out GREAT, and it's much easier to clean and takes up less space. It only takes ~3 minutes to make a full batch.

The key is to use coconut oil and butter salt. Yum!

That's true -- but I'd rather put that money towards a pin.

Like I said, spend the $20 on the Whirley-Pop until you figure out what you want to do longer term. It's cheap, and the popcorn/oil/seasonings you buy will work in any future machine you may buy. Until then, you'll be able to enjoy theater-like popcorn.

Not sure where to find it (I do all my shopping on Amazon...)

I like this brand: https://www.amazon.com/Paragon-Butter-Flavored-Seasoning-Salt/dp/B002YLGAIO

I use a cap-full for each batch of popcorn.

Then for oil, I use this:
https://www.amazon.com/gp/product/B00CPZPYLS/
or this:
https://www.amazon.com/Wabash-Valley-Farms-Popping-Oil/dp/B002EITVVA

Then buy some Wabash Valley Farms Amish Country popcorn, and you're done. There's a lot of different types, so experiment to find which ones you like best. My wife's favorite is the baby white (not many hulls and they're tiny). I really like the blue popcorn as it's a little sweeter. My all time favorite is Strawberry popcorn, but I don't think the farmer had a harvest this year. http://jacksgrainandgourds.homestead.com/

This is how I do it:

Don't heat anything up ahead of time -- put the oil (only 1 tablespoon), the butter salt (teaspoon, maybe less depending on how much you like), and the half a cup of popcorn. Turn on the heat, spin it for about 3 minutes (until it stops popping), and you're done. I'm thinking heating up the oil ahead of time (and using 50% more than I do) may have made it chewy.

The type of popcorn probably factors in too. Don't use Orville Redinbocker or any of that junk. Find a supplier of high quality kernels if you haven't already. Wabash Valley is good, but you can find others as well.

I've said it before - the Whirly Pop is awesome, doesn't take up much room, makes amazing popcorn, and is cheap. I personally don't see the need for a dedicated machine that will always take up space, unless you want it for decor.