Alarm for my Jeep

[SS Teacher 177]

My soft top Jeep wrangler has been burglarized 4 times now at my crappy apartment complex.  The thieves have never stolen anything valued over $30 but I'm tired of feeling violated.  I know there are some shop owners and installers here, what are you guys thinking?

All my car audio stuff is bolted/chained down; I'm looking for a very basic alarm with door open sensor and some kind of proximity alarm for when the doors are off so the thug/piece of human filth hears the alarm and runs off without rummaging through my stuff.

I have a manual transmission and no power door locks or windows so I'm not interested in paying for anything high end, but I do like quality.

I called two local shops I trusted and they quoted me $350-$400.