You can get alarm panels with key pads, battery backup, motion sensors, switches and about all you need for around $70. Then add $20 for a loud siren and you should be good.

One thing I did to our cabin (in the middle of nowhere) was to put the alarm switch on the unlocked screen door. Bad guys will open the screen door, the siren will go off (then probably pants are soiled) and they then leave. Nothing gets broken and the bad guys are discouraged. We initially had the switch on the inside door but then we still had to fix a kicked in door even if they didn’t seal anything.

If you don’t have electric to the place you could probably get a solar battery charger off eBay for around $30 to keep the battery charged. I got one that was used to keep a new Volkswagen charged on the boat ride to the USA from where ever.

Our alarm system even caught some bad guys once. They opened the door, the alarm called us, we called the cops, the cops found them hiding out in the woods with loot from other cabin break-ins.