Multiple colors of AmazonBasics 3D Printer ABS filament is on sale today. I’ve personally used this stuff, and it exceeded my expectations for budget filament. With multiple colors available, I highly recommend it at $19.
I have more experience with 3D printers than a man deserves, so I can tell you that this isn’t going to turn out flawlessly smooth prints. But it will turn out good prints and an amazing experience of learning exactly how a 3D printer works at an incredibly low price.