Toktz-ket-xil is an excellent ranged defense for OSRS Gold a short penality for attacks that are ranged. Not a bad trade-off. A Ring of Life - Mainly for lack of anything else to offer. Things could go horribly wrong and I've got expensive items. I may replace with archer's the ring should I ever need to buy one.
Here is my inventory before I go out of the banking 2 ranged and 2 Super Defense Potions. These speed my travels. I keep them in my bank and replenish after the effects of my last dose are gone. 16 Monkfish - My staple meal to start with. As I eat, I replace them with bones. 1 gp/50 nats/Fire Staff I have a stash of all non-stackable objects and, if I require more Nats (I seldom go through many) The Aviansies drop more.
Trollheim Teleport - Well, in order to access the God Wars Dungeon. These inv. slots are replaced by Adamantite Bars or Broad-Tipped Bolts. Mithril Grapple is for getting into Armadyl's Esyrie (and pretending I'm Luke Skywalker). Varrok Tele-Tab – For easy access in the Grand Exchange to sell me things. Ten Bones to 10 Peaches Tabs - To replenish my supply of food after eating the monkfish.
In the same way I'm staying through eight doses of Ranged Potion (my defense level never gets down to its initial level which is why Super Defence Potions are cheap anyway). It is common for me to get a hint in 3 out of 4 runs, and typically wait until the next one to ensure that I am finding another. I usually get my kill count to around 100 in one run, which is about 325k of profit.
You'd like to offer items that are stable and a predictable pattern. Something that rises and drops in a predictable manner. To find out when things might increase or decrease outside of Old School RS Gold this cycle, search for big updates such as weekend xp doubles or new quests. Consider merchandising items that many people use for skilling, and do it in bulk.