Board Thread:Questions and Answers/@comment-6016076-20140720081239/@comment-6016076-20140727212630

So I did some math myself. I assumed that the Advisory is a 50% increase like the Monkey Bank was (and all of path 1). Summary at the bottom.

For the bank route (path 2):

Best combinations of Bank

0/3 and 0/4 are now the best combinations. If you are building directly into either of these, there is no reason to upgrade any of path 1. Because there is a 1.1 exponential increase, the 50% increase in base gold value does not translate to the same approach to the threshold limit as in BTD5. It turns out that 2/3, 1/3, and 0/3 as well as 2/4, 1/4, and 0/4 all reach their respective thresholds on the same round. 1/4 will pay for itself on the second time around you collect (16 rounds); a 2/4 after 234 rounds.

Collecting early with Banana Plantations (Path 1, Tier 2)

Potentially, you can collect a round earlier with 2/3 (but not 2/4) for a marginal gain in gold per round (19 more gold/round), but in terms of gold per cost, you will need 90 rounds to break even for upgrading Banana Plantation, so there's a cost if you want to collect a round earlier.

Banana Investments Advisory (Path 2, Tier 4) vs. Banana Research Facility (Path 1, Tier 4)

An Advisory collects after 8 rounds. A 0/4 will turn 2900 gold greater profit over a 4/2 after these 8 rounds, accounting for costs. This means a 4/2 theoretically overtakes a 0/4 after 12 rounds. After 16 rounds, the disparity is 12,600. Of course, you need a 9000 gold greater initial investment to build the 4/2 (64% increase in costs). If the Advisory's lower costs mean you build it 4 rounds sooner, then it will give you greater profits over 16 rounds, which is pretty much an entire match except CT.

Of course, if you are building in terms of cost, you can build three 0/4 per two 4/2, leading to about 25% more profit per round with the Advisory.

Monkey Bank (Path 2, Tier 3) vs. Banana Republic (Path 1, Tier 3)

A Monkey Farm collects after 6 rounds. A 0/3 will be behind by 800 gold profit after 6 rounds compared to a 3/0. After 12 rounds, A 0/3 is ahead by 2200 profit. The investment cost for the 0/3 is an additional 3800 gold (77% increase) over the 3/0. However, relative to their costs, the Banana Republic will always give you a better profit. Of course, a 2/0 still beats a 3/0 for cost efficiency.

A 2/3 will be behind by 2400 gold profit after 6 rounds compared to a 3/0. After 12 rounds, a 2/3 will be ahead by 700 gold profit. The investment cost of a 2/3 is 5500 gold (171% increase) over the 3/0.

Summary


 * 0/3 and 0/4 banks are the best.


 * If you can get a 0/4 four rounds before the Research Facility, it's better to go 0/4 assuming it's a 30 round match.


 * Monkey Bank is still inferior to the Farm; however, its cost differential isn't too large for the scenario of a 0/3. Consider selling your 2/0 instead of upgrading it to a 2/3. Then build a 0/3.


 * The gold tradeoff of a 0/3 is 800 gold worse after 6 rounds; 2200 better after 12 rounds.   The time tradeoff is waiting 6 rounds to collect each time.  Also, there's a 77% greater initial investment, so you will likely only want this if you are far ahead in gold and need to go the bank route for some reason.


 * The gold tradeoff of a 0/4 is 2900 gold better after 8 rounds; 12600 gold worse after 16 rounds.  The time tradeoff is waiting 12 rounds to collect each time.  You will likely want this if you cannot get a Research Facility for at least four more rounds.

If you are going for Contested Territory and plan on surviving for many rounds past 30, there's virtually no reason to go for the bank unless you sell the 0/4 for a 4/0 after 8 rounds collecting. Again, if you are 4 rounds away from getting a Research Facility but have cash available, build a 0/4; then you can sell it after 8 rounds and build a Research Facility, saving at least 5000 gold in the process.