You need to think big if buy RS Gold.
You do not need a higher farming level to start planting money making herbs, you can get close to level 50 farming very easily, and after that it's simply a few looking into the Runescape Grand Exchange as to which herb provides you with the best returns. I'd tell you here and now however it changes constantly so you will need to research it yourself. After this, it is a case of doing a 10 minute farming run in which you plant all the herbs, and then proceeding to catch red chinchompas while using hunter skill. Catching red chinchompas takes level 63 hunter which is really low considering they're worth around 800gp each. Contrast by using yew logs which takes 60 woodcutting and are worth 450gp, or fishing which takes level 73 for sharks which are worth only 550gp each and you will see right away that you're onto a success.
The secret to Runescape Gold making on Runescape is all about maximizing your time to maximize your profits. A 10 minute farming run doesn't take very long to actually do, however the growing times are around 30 minute which means it might take 40 minutes for just a 100-150k gp in profit.This really is pretty terrible money, but rather than holding out to allow them to grow utilize your time and plant the herbs and go catch some red chinchompas. You can earn around 250k each hour using farming, but when you're catching red chinchompas at the same time you can easily boost this close to 800k gold an hour. It takes incredibly low skill levels, it doesn't take much effort and it definitely takes care of money-wise!