Method

The following setup will maximize total profits when all things are considered, note that a lot of the optional improvements marginally contribute to the final GP rate.

for every hour of fletching intended:

It is recommended to fletch for many hours at a time as to minimize the cost of switching between agility obstacles

Ratios

For each hour of Fletching you'll need to spend (on average):

and it'll generate 50,297 Dragon Javelins, selling for 32,693,142 GP and leave as byproducts:

and consume:

It is recommended to combine   Circlet of Rhaelyx and   Jewel of Rhaelyx into   Crowns of Rhaelyx and selling them using Item Alchemy III and GP boosting items, this will add (per hour of fletching) 0.02 seconds to sell crowns and 0.04 seconds to sell the leftover   Jewels of Rhaelyx, with the profit from that and selling the other leftover elements normally you'll end up with a maximum possible output of 18,265,154 GP per hour all things considered.