(Updated) NEVSBYE Filament.
About 50+ options at the promo link, including PLA, Matte, Silk PLA, PETG, TPU and ABS... easiest to just start with this post from the Promo Codes Page which has them all listed with prices.
Price after 15% off promo (code DSW3T7WW at checkout).

some colors had a price drop overnight 🙂