No unintended access of a gun is worth going cheap on a safe. Either a child or person's life is dependent on what you spend, or a thief's ease of access (threatening others' lives) may depend on what you are willing to spend.

Be responsible. Save up. Lock it up. With quick access. Stay away from batteries, that WILL fail. It only takes one to leak and your screwed for quick access.

I like:
V-Line | Security Cases and Cabinets

Simplex lock 5-button mechanical access. Mounting plate for removal and transport available. Other manufacturers also use the Simplex lock system and have somewhat different designs, quality and prices.

Bolt the safe to something solid so the whole thing cannot be taken. Think like a thief to overcome a thief, not like a homeowner. How would you steal those guns?