It's like old folks undies--depends.
If your labor is worth anything at all, buy them. Elite sells very good parallel arrows for around $50/dz.
If you like to fiddle with them, your cost will be around $35/40 dz, if you use the very best materials. I like to do it, so I make multiple dozens per year. You can never have enough time or arrows!<img src=icon_smile_big.gif border=0 align=middle>

Your life is made of time, not money.