When this does happen, are they usually running as multiple bot tabs in the same mirror client, and they all fail on this step? I see you have 8th bot tab in there, which makes it difficult for the mirror client to manage memory since all tabs share the same memory space when ran in the same mirror client, and it can often produce random errors when it fails to load NPC/Object definitions; It's best to open only 1 bot tab per mirror client (start multiple mirror clients instead), and if the mirror/official client for any reason has very high RAM usage, restart the clients before running a script;
The ironman mode should work for this, press F5 while the GUI is open, the window title will switch to Stealth Quester (ironman mode) and for the supported quests it will collect required items instead of buying them from the GE