Ultra-cheap (but tasty) microwave popcorn

Step 5 FAQ

Q: My brother-in-law uses paper sacks to do this without oil, why don't you?
A: Paper sacks aren't designed to be put in the microwave, I'm not sure what's in them (chemically speaking) that may be bad in the microwave.

Q: That's not enough popcorn, I want more! How do I do it?
A: That depends... You can buy a big microwave popping container and use that to make lots of popcorn. But since I'm cheap, I'm using what I already have. You can try other container sizes and times, just be careful not to burn yourself (or the popcorn) too much.

Q: Can I just cook with butter and skip the whole vegetable oil thing?
A: I think that's too prone to burning, so I didn't try it. Also, I would expect it would be difficult to clean, so again, I didn't try that.

Q: Can I put the salt in with the oil and popcorn?
A: I wouldn't. I tried and it made a mess that was difficult to clean.

Q: Can I collect the unpopped kernels and try again?
A: Not likely worth the effort, they probably are duds anyway. (Thanks razordu30 for the info!)