I would say, for each healing pot or jerky brought increase the price; the price goes back down over time when not being brought. Likewise, for the effect of the health restoration, each item used decreases the effect with the effect increasing back over time (for that unit).
For instance..
I buy 2 jerky for 100 on turn 1.
-Jerky price goes up to 110 then 130.
I use a piece on turn 1 and get back 100 health.
- I eat a second piece of jerky, I only get back 90.
Turn 2, the price of jerky drops down to 115, and the healing effect (for me) increases back to 95.
-If I wait another turn, price and effect return to base. But if I buy another jerky, the price goes up to 145. If I use another piece, the effect drops to 75.
This would allow people to still use them in mass quantities (after all, later on, you're gonna have a lot of troops), but forces them pace themselves and decide who really needs the healing.