I've seen fake alarm systems which basically are stickers, SIGNS "(This Property is Under Video Surveillance" etc), and even flashing red lights that are battery powered-battery powered alarms - they have these at harbor freight, you can put on windows and doors- they're powered by magnets --Does anyone have recommendations for better battery powered or simple DIY alarm systems?

I actually forgot to include that part on surveillance in my comment, great idea.

Some apartment buildings in my area do rent for more than multifamilies because they have a 24 hr doorman, laundromat, garbage chute, video surveillance doorbell, parking, gym or salon. 

Police chases almost every week in the news papers, a rapist just caught a few weeks ago after raping a girl down there.My tenant has installed a surveilance system because someone tried breakining in a couple times. the guy still periodically walks right up to the door and tries to get in.

Within two years or less, we will witness a major market crash caused by a combination of another pandemic and war, and more cyber attacks on our infrastructure.

They have vetted and disclosed their processor, they maintain a strict cyber security protocols, etc.

We went with butcherblock countertops because they were on a Cyber Monday special from Menards and we could install them ourselves. 

So no membership discounts today or on cyber monday?

You could offer surveillance cameras to help them feel more secure.  

I actually just bought Crushing It yesterday to take advantage of Cyber Monday.