Help finding an old concept; natural RAW result being magocratic city-states

[Satinavian]

Core as core can be, use-activated magic item. SL * CL * 2000 gp.
For Teleportation Circle, 9 * 17 * 2000 = 306,000 gp.
For Create Food and Water 3 * 5 * 2000 = 30,000 gp.

https://www.d20srd.org/srd/magicItem...MagicItems.htm

I am not sure that is it. Those use-activated items do come with a multiplier for duration or are single use per day. (And thus are more expensive than eternal wands or pearls of power as non casters can use them.) The once per round resetting traps must be from something more obscure and specific. There is a reason it is called traps. It is from some utterly unbalanced trapbuilding stuff that never considered beneficial apprications.