I buy all my cedar shafts from Valley Traditional Archery. I have bought many dozens from them and have never had one that wasn' t shootable. They are very straight and if you get them hand spined and weighed, they will be +/- 5 gr. for the lot. They are $18.95 per dozen for hand spined and weighed. Great folks to deal with and the quality of the product is top notch. I am sure there are other great dealers out there but I bought my first dozen from these guys and have never tried any others for shafts.
http://www.valleytradarchery.com/