What advancements are the best? Which ones are to be avoided/delayed?

I'm still in Phase 1 so only have those to choose from. To me, it seems the Increased Army Camp, Joint Strike, and of course Increased Idle Time are the priority, while the increased ore production & sell values are way down the list.

Now in, "The Siege of Feldmere". Half way through with little to help continue the fight. I feel the second half will take me many days at this rate. 3 mercenary camps exhausted, no more to buy, need more of them in proper locations to continue? Recipes are far away, still need more to make needed items in usable time frame, still searching.

Don't buy mercenaries at the begin, save them for after you have finished exploring the map and instead buy army camp upgrades instead of mine upgrades.

Sometimes it's worth it to sell all your ores and alloys just to buy the next army camp upgrade.

Edited 7/31/2020 20:07:27

I would like a wiki page with the ap costs of the next levels of advancements.

They seem to decrease a random amount of ap after the first purchase and then increase in ap at some fixed rate.

I can't make out the ap price of the next level with my current knowledge.

Always do the math on all mercenary cost decrease advancements.

"Advanced negotiations" (decrease mercenary cost by 15%) for example would cost me 6.6 billion worth of material to produce the necessary items (or 48.6 billion if I bought the necessary items at the market instead).

The most expensive mercenary camp in the map costs 68 per army. Fact aside that it was long depleted before I could even buy or produce the necessary items, you would have to buy 6.6/0.15/68 =~650 million armies to break even on the 6.6 billion spent (or 4.8 billion armies if you were crazy enough to buy the items). Hardly possible with a camp that holds only 400 million to begin with.

I maxed joint strike and autoconquer to beat all challenges for extra advancement points then reset ap distribution ( had +- 8000ap then). Now when autoconquer is useless i put all points in increase army prodaction (300%) extra cache money (max) joint strike (max) and increase ore sell price (max).
now hurueys castle takes me an hour to beat but only gives me 4 ap