I'm always very afraid to decant paint into any kind of plastic jar. I'm perhaps being overcautious, but I have had plastic containers melt after decanting.
As far as the glass jars, you can re-use them. Here's something I posted on another thread:
Get some Super Clean or Purple Power at your local Walmart. Fill a glass
jar about the size of a mayonnaise jar about half full. Drop the small jar
covered with paint into it so that it is completely covered and let it sit a couple days. Take the small
jar out (wear rubber gloves, this stuff is nasty to your bare skin) and
rinse in tap water. Rub off any stubborn bits with an old toothbrush.
It should look like new again.
This cleanup trick will work for a plastic jar too.