12ga is definitely worth reloading if you shoot a lot. I will go through 2500-3000rds a summer, and I figure it is costing me about $3.70 a box right now. My reloads are using components which are very similar to a Winchester AA heavy target load, which are now selling for around $7/box. Now just for backyard trap, or gravel pit blasting ammo, you're probably not going to notice the difference with the value pack ammo from walmart.