Prime Members: 4-Ct 1KG SUNLU Easy PA Nylon 3D Printer Filament (Black) $56 + Free S&H

Thumb Score: +17
Sunlu via Amazon.

Comes out to just shy of $14 per kg.
Price is only for Prime MembersProduct Link [amazon.com]
This supposedly prints much easier than other engineering filaments. Some reviews here [amazon.com].

Here is a detailed Youtube Video [youtube.com] where the person compares it to PA6-CF & PA12-CF