Monoprice has 0.5kg MP Select PLA Plus+ Premium 3D Printer Filament 1.75mm Black on sale for just $5.58. They also have $25 off $100 promo code 25MORE. This means you can get 18x 0.5kg spools of filament for just $75.44, or $8.40/kg.
I almost exclusively use monoprice filament since they consistently go on sale throughout the year and are of good quality. I typically go through ~4kg a month.
Deal instructions:
- Add 18x of 0.5kg Monoprice PLA+ (Black) to cart
- Apply promo code 25MORE in cart
- Your total should be $75.44