This week on the woweconomy subreddit someone posted a question. They had 2 million gold and wanted to invest it in items that would go up in price over the next year. To me even asking such a question on a public forum just shows that you are not yet at the level to do it.
Guides can’t take you all the way
In every area of life with a skill component you will typically gradually gain skill. For the first part of the skill curve you can follow guides and pre-determined recipes. Past a certain point however, the area gets to exclusive, and any further progress will be found by blazing your own way. No one can give you a recipe for making multiple gold caps, as at that point you have to adapt to your situation to truly be successful.
Investing for the future is one such area
Investing for future patches is definitely one such area. First of all it is essentially impossible to know how prices will react to gameplay changes. You can have theories of course, but you cannot know. Since you can’t know and the actions of others will impact how well it works you will have to come up with your own analysis here. Even if someone else knew the future, it’s not really in their interest to tell you the truth either.
When taking risks, only rely on yourself
You are putting significant capital at risk if you invest for future patches. You have to face that risk head on. Since you can’t know the future, you should at least rely on your own analysis to make sure you know what kind of risk you are taking.
Investing is not that important
All this being said I have personally found that investing for the future is not really core to successful goldmaking. It can work, but I have generally had much more success with steady state goldmaking in markets that just work over time. Mature markets will keep you going and will be the best way to make gold long term.