You're the one saying they cost an astronomical amount that would preclude poor people from affording them, but that seems refutable by the fact that GPS trackers are commercially available for truck fleets[0] as well as tracking pets[1]. I see nothing over 200 dollars. So show some sources if you really think GPS trackers would be prohibitively expensive as currently deployed.

[0]https://www.gpsinsight.com/gps-tracking-benefits/what-is-the...

[1]https://www.pcmag.com/roundup/354245/the-best-pet-trackers-a...