-- Town merchant buy pricing: higher gold costs, ±15% roll per offer (see tuning Defaults / RollTownMerchantOfferGold).
-- Sell-to-vendor remains autoSell* in runtime_config (unchanged).

UPDATE public.runtime_config
SET
    payload = payload || jsonb_build_object(
        'merchantTownGearCostBase', 180,
        'merchantTownGearCostPerTownLevel', 40,
        'merchantTownGearPricePerIlvl', 115,
        'merchantTownGearPriceVariancePct', 15
    ),
    updated_at = now()
WHERE id = true;