The fonts on some of the envelopes appear quite modern. Some of the patterns could have originated in the 1930s yet not be original prints. It almost appears as if someone had belonged to a pattern club and received periodic mailings or some individual had a business selling traditional patterns. I remember when patterns were hard to find except for Mountain Mist and a quilter had to draft from examples in books like Marguerite Ickis or The Romance of the Patchwork Quilt. It was a wonderful day when Quilters' Newsletter was launched in black and green ink and then full color.
The other possibility was that the original owner collected the patterns offered in newspapers and other periodicals.
Perhaps the $100 is a typo.