Expanding isn't just about increased gold income. The problem with upgrading is that they are horribly inefficient due to upkeep. Obviously, upgrading to houses will provide
way more gold than a tent, but the resources you'd spend on tech upgrades could have been spent going further into the tech tree, or beefing your base, or building even more buildings.
Code:
Tent
- Upkeep: 4 Food, 1 Energy
- Provides: 2 Workers, 8 Gold
- Cost of each +1 Gold:
- 0.5 Food
- 0.125 Energy
Stone House
- Upkeep: 16 Food, 10 Energy
- Provides: 8 Workers, 40 Gold
- Cost of each +1 Gold:
- 0.4 Food
- 0.25 Energy
Mill
- Provides: 30 Energy
- Supports:
- 30 Tents = +240 Gold
- 3 Stone Houses = +120 Gold
Stone House requires 20% less food per gold, but 100% more energy. Banks and Markets help a lot.
But really that's the beauty of the game. Eventually you get a "feel" for when you should do this or that