Oh! If your RS Status is currently freeplay, you'll not be OSRS Gold able receive a clue Scroll drop. The drops are only available to registered players. But, I'll assume that you haven't updated it.
For money-making, I have always found that runecrafting is the best method to earn it. Even if it is not possible to craft the most advanced runes like natures or enchants airs with lower levels of difficulty can still prove profitable. However, it will require a lot of time and be boring. Other options include learning how to cut wood to level 60 at draynor. Next, you could cut yews, which is extremely profitable.
Two potions for prayer are required for crossing the island. You will also need 4 anti poison potions. Cammalot teliportation runes are a great idea. They saved me from eating my entire food!
For the underground part, four prayer pots, four super energy potions, two anti poison potions, all the things required for the quest, and then the remainder including food (if you are able to keep yourself safe from mellee on all the time, you will do well). Keep an eye on your running and when you reach 50% drink a dose or two of run energy, when prayer is at 28% drink a prayer potion, eat when needed!
For demons For the demon: One anti poison (for the time you're teleported into middle of jungle), camalot running runes (for afterward or in case demon somehow manages stay alive :cute ), 4 prayerpots (over kill but safer to be Buy RS3 Gold safe than you don't) and the rest good food.