Here's the deal: :-)
The supplier they had before had issues with the sizes of the F4's. A lot of them were smaller than 18x22. So, they are getting rid of whatever F4's are left (that's why they were 99 cents for so long) They are getting a new supplier, and most Jo-Ann's should have a new stock of F4's sometime in February.
Not to worry everyone! The F4's will return to Jo'Ann's!! :-)