My wife bought me a dehydrator for Christmas..... after using it a few times making jerky.... it "paid for itself.' I needed a dehydrator anyhow.
Using the stove..... you only set the oven at 110 (with the oven door cracked slightly) for about 1hr to 1 1/2 hrs. Of course, I made my first batch of the fall (didn't need the AC) in the oven, and the rest in the dehydrator (didn't notice any spikes in the power bill. I stuck several pounds in the freezer (had too, it's addicting to eat).
The Eastman Outdoors jerky is absolutely AWESOME. I wanted to use "store bought" seasoning packages before I started experimenting with scratch made recipes...... but for $4.50 a box and the flavor.... can't beat it. So I added several boxes to my pantry with the rest of my stores.
Is the dehydrator useful for fish?
I wouldn't go overboard with the fat though. Also if you are using a jerky gun (pretty cheap at Wal Mart), people seem to prefer the tube "slim jim" pieces of jerky vice the thin strips. I usually make half and half.
Dehydrator and packets of spice. Check. What cut of meat do you like?