Buy RS3 Greenman's ale
Greenman's ale is a drink in RuneScape 3 that gives a small but useful boost to your Herblore skill. When you drink it, your Herblore level goes up by 1. This lets you clean herbs and make potions that are one level above your real skill. It also heals 290 life points.
The boost comes with a small cost. Drinking the ale lowers your Attack, Defence, and Strength by a few levels for a short time. This does not matter much if you are training Herblore at a bank.
Players can brew this ale at level 29 Cooking using clean harralander, ale yeast, buckets of water, and barley malt. Buying it saves you the time and supplies needed to brew it yourself.
There is also a stronger version called mature greenman's ale. It boosts Herblore by 2 levels instead of 1. The regular ale is still a cheap and simple way to reach a potion just out of your range.
Fun fact: the cook in Lumbridge Castle says Greenman's ale is the official sponsored drink of Castle Wars.