What species of fish? Most fish will be just fine for a week w/o food. I usually just do a water change before vacation then they’re left to fend for themselves. So far everything has been fine when I come back.
I can agree with that. Auto feeders are rarely necessary. Big water change before you go, keep sunlight out of the tank while you're gone to stop algae build up. Feed 3 times (small meals) the day before you leave and you're good!