you would have to raise your own. Which costs about the same as using F/T, but is incredibly more laborious and stinky.
Not sure you speak from experience on that but by raising my own feeder each feeder only cost me 1/3 of the cost of a F/T.

The advantage is also to know that I provide the best quality food possible.

I had the opportunity to visit a large feeder breeding facility and what they were using in addition to feed was just scary.