2013, boosting fob signal when parked to enter

I haven't posted in a long time. I know this is a covered topic, to a certain extent.

Due to the bad guys boosting key fobs signals trick when your car is parked, I'm disabling the "Key System with Elec. Key" feature in the car vehicle settings. My Prius has been rifled through twice (that I've known) since I've owned the car. I don't think to wrap the fob in a foil, using a faraday pouch or putting it in a can @ night is practicable long-term. I don't feel like investing in an alarm system, considering this car is older now. Is there any downfall to disabling this setting? Could a bad guy/gal still figure out a "Rfid" workaround without causing physical harm to the car (smashing a window) to get in? l I understand I need to hold the fob to the button to start now. Could a thief still use the fob signal in any way to get into the car?

Anyone have any better recommendations, please let me know. Was about ready to plunk down $400 on an alarm but I'm hesitating on what good it will really bring. I don't stay connected with this group much; however, I know this is the place to get answers/suggestions. BTW, I don't leave valuables in the car.
brian