Area 3

In Area 3, there are two new businesses for the player to work with, those being: Barber Shop and the Snake Oil Business. The special thing about this area is that every other unlock for most of the businesses, they help out one of the businesses, then themselves, then the next business in line, and repeats.

I.e.:

250 = 100% Profit

300 = 4th business 100% Profit

350 = 100% Profit

400 = 5th business 100% Profit

etc. ..

The beginning pioneer upgrades (up to 10 ac) in area 3 are very similar to those in area 2, with the main differences being the lower all profit multipliers in area 3 than in area 2.

Note: Area 3 is the last area to introduce new stuff. All areas past that are mostly a copy of one of the first 3, with a few changes.

Also note that area 3 has similar cash upgrades to an old version of area 1 and nearly identical pioneer upgrades in the early-middle stages.

IMPORTANT WARNING:

There is a problem with Area 3 that can really ruin the game for you!

The problem is that if you finish most towns in the Area at (close to) maximum population, your progress towards the end of the Area will become exponentially slower each town, potentially to the point where it is practically impossible to finish the Area.

To circumvent this you should try to stay below 1 ba pioneers until at least town 55. This should allow you to comfortably finish the Area without further problems.

This article contains a complete list of all business upgrade bonuses as well as milestones for upgrading all businesses of a town to a certain level.

This list is up-to-date for the current version of the game (v1.13.4) and was written by Ampelphase.

All-around bonus
This video shows the complete list of cash upgrades, and as many pioneer upgrades that could possibly be shown.

Videos for each town