I think you've gotten enough responses resounding absolutely no. The seller probably looked at retail stickers that may still be on the patterns and added them up coming to the magical number of $300.
I wish I could get what my house was worth just 3 years ago, but reality is, you only get what the market will bear and IMHO that includes a binder full of patterns. Used or opened or not opened, his sky is a very different color than what in reality it truly is.
The seller likes these patterns too much and therefore will probably keep on owning them.