If you visit a TCM clinic for consultation, most of the time you will get pre-made Chinese medicine in the form of bottles of powder, pills or liquid. This indeed provides some level of convenience to patients since they would not need to go through the trouble of preparing the medicine themselves. As humans, we all like conveniences. However, there are times when we should forgo convenience for the sake of something important, and this is one of those times.
The most obvious factor to account for would be the price. The herbs cost money. The process of making these powder, pills or liquid packs cost money (not forgetting that there are research and development cost hidden in the price as well). The shipment of these medicine cost money. All these add up to a large sum that consumers do not seem to realize. This is because each bottle of powder, pills or liquid cost a few dollars only, but how long do each of these last us? On the other hand, buying the herbs and cooking them would save us much more since one round of cooking the herbs can yield us enough medicinal concoction to last us for a few days and how much would a pack of herbs cost? Probably just over a dollar or two.
Another problem with pre-made medicine is that because because they were made before the doctor ever met you, the doctor can only choose the medicine that is the closest fit to the answer for your condition, and not the exact fit. Here you take a longer time to recover, since you have to go back to the doctor for another round of consultation and medicine, and since you spend more money.
Thirdly, because of the way these pre-made medicines were created, their efficiencies have been compromised. Pills are usually the grounded form of herbs compacted into one small body. They have to be made beforehand, so they are the least flexible in terms of tailoring them to suit the patient's needs. However, sometimes herbs need to undergo the cooking process before the essential compounds can become active, and the amount of herbs that can be packed into that small pill is limited, making it harder for effective treatment levels to be reached. Then there are the bottles of liquid medicine. These come in two sorts – the tailor-made ones are done by cooking herbs under pressure for a few minutes, meaning you get diluted contoctions or the pre-made versions that are concentrated but not specific to your body's needs. Lastly, the powder form also comes in either the pre-packaged form or those lined to suit your needs. The powder form is either made from grounded herbs or from cooking of the soup and removing the water from it such that powder crystals remain and the addition of water re-creates the concoction again. The processed powder form is the most ideal form of pre-made Chinese medicine, but it is also the most costly form.
Considering both cost and drug efficiency, I would say that cooking herbs by itself is the best choice to take if one has the time, as it has the highest treatment efficiency and is the cheapest option available. However, if you do not have the time or want to go through the trouble of cooking the herbs, do not reject the thought of pre-made medicine as we are all human and need conveniences.