Raising feeders is only a reasonable solution if you're operating on a certain scale, or you have a plan for how to recoup the costs for raising excess feeders (since you're wanting to use rats). If you are going to be spending money on bedding and food, you want to make sure it won't cost you more than your snake's current $5/wk mouse habit.

Now, if you are driving 20 miles to pick up those feeders, it may make more sense considering gas being around $3.10/gal, but do the math first before jumping into something that is far from the free lunch it seems like on the surface.