I find sizes 3-6 useful. I use them all the time. If you use sport/dk weight yarn, you'll need them. Even with worsted you often start a ribbing with a size 5. I'd say to get them.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry