I bet all Clash of Clans players think about the question “Should I upgrade those Gold Mines and Elixir Collectors?” at least one time. This is always the hard question for not only new players but also elite ones. We will discuss about it in this small topic :D. This post is based on the comment of purpleclouds on Reddit.
In my opinion, you should upgrade your Collectors whenever you can because of their sweet passive loot gains.
If you farm a lot, Do you think that you really don’t need to spend resources on upgrading those Collectors because you always have enough loot to upgrade the main buildings? Why not spend small amount of that loot to upgrade those Collectors and get extra passive loot everyday? If you are a lazy player, you will really need the extra passive loot that maxed out Collectors offer everyday.
No matter how you play the game, you always need them. The initial investment of upgrading collectors takes a bit of time to pay for itself. By doing some basic calculations, we can easily see that it just takes about 30 days to catch up the initial investment of level 12 collectors. Also, after upgrading, the collectors will have more HP so your base will be much stronger. The extra HP entirely can make the big difference in defense.
Here are some amazing facts for you:
With maxed Gold Mines and Elixir Collectors at Town Hall 8 and 9, you can earn up to 504,000 and 504,000 everyday and it will be 588,000 each at Town Hall 10.
With 2 maxed Dark Elixir Drills at Town Hall 9, you can earn 4800 everyday. It means you can have enough to upgrade Golems from level 3 to level 4 without doing anything after ~16.5 days.
All in all, upgrade your collectors whenever you can, of course after your main defensive buildings!