You can check out
https://marshalldrygoods.com/. They have solids called Dream Cotton. I like them and so do others apparently and they are reasonable. They don't have the color selection that Kona does, but they have quite a few. I have bought some basic colors by the bolt. If you buy a bolt, you can get it for I think it is $2.99 a yard. By the single yard it is $4.49 a yard.