If you want a palette that has more matte options, then I would purchase this one. The Naked palettes have a lot of shimmer, and this palette does not. It's a great add-on for some matte shades that will complement your look.
In my opinion I feel that it is worth buying. I think it is great for a natural look. I love my Naked 2 palette, but sometimes I can go without the shimmer. Naked Basics provide a more soft and neutral option.
No. I think having the other two is enough. I feel like this one is a smaller version for the people that don't want to spend the $50.00 for the full size palettes. Thats maybe why they called it "Basics". Maybe its the essential colours from the full size palettes.