I live in Hawaii, where shipping adds a large amount to get products here. Our prices are always higher than you would pay "at home"!
The local LQS has Warm & Natural 90" at 12.99 a yard -- that's 90 x 36, much larger than crib size. (The 45" $6.99 per yard, which you mention is what you remember paying - the price is the same -- you get twice the battling for the 90".)
For the SAME PRICE and size -- Richland 100% Cotton batting....
The big stores on the mainland (neither of which have any stores at all in our state) have raised their "everyday price" to make you feel "good" when you get 40% off. It's a marketing thing....
I agree that you need to use 100% cotton for the microwave items -- we recently heard from one of our customers that the polyester thread she used caused a fire in the microwave.... so the 13% non-cotton in W&N is way too much!
PS: that percentage "off" by using continual coupons (like at Bed Bath & Beyond, as well as fabric stores ) has increased the "every day price" on your fabrics too.... Better grab and use those discounts!