According to page 229 of the sixth printing of Tactical Operations: Advanced Units & Equipment, each ton of remote sensors (presumably sixty of them) costs 25,000 C-bills. Rather than leaving them behind wherever you set up a security perimeter, could you pick them back up and load them back into a Remote Sensor Dispenser?
The fluff on page 186 implies that retrieving them outside combat is common, as their battlefield use is rarer due to being expensive and easily destroyed. If they couldn't be picked up anyway, their destruction wouldn't matter much.
