Compare the cash decision: buy an upgrade, fund research, or keep saving. This tool accounts for purchase cost, your protected reserve, any wait to afford the option, and the next cash goal. It does not value unmeasured access, drop odds or character rarity.
Start with a fair cash sample.
Enter your values and compare. You will see income change, extra-income payback, time to afford each purchase and time to your next cash target.
Inputs changed. Compare again to update the decision.
FOR THIS CASH GOAL
| Path | Cash/min | Income change | Extra-income payback | Wait to afford | Time to cash goal | Cash at horizon |
|---|
Payback is measured from the purchase. Goal time includes any wait to afford it. The model assumes constant net rates, no other purchases and an immediate rate change after buying; it is not a guarantee of future earnings.
Rerun with conservative income inputs →What each result means
Extra-income payback
Cost divided by the added cash per minute. If a 100-cash purchase raises income from 10 to 15 per minute, payback is 100 ÷ 5 = 20 minutes after purchase. Dividing by the full 15 would ignore the income you already earned.
Time to your cash goal
The tool first waits until the purchase can preserve your reserve. It subtracts the cost, then earns at the after-rate until your desired total cash balance is reached. It compares that time with saving at the baseline rate.
Zero or lower income
A paid option with no added cash does not repay itself through extra earnings. A zero after-rate cannot reach an unfunded larger goal. With zero baseline income, a purchase shortfall has no funding route in this model.
Access-only research
A prerequisite or zone unlock may be useful even without measured cash gains. This tool evaluates cash paths; use the research dependency guide for access decisions.
Read the formulas
Baseline rate = before earned ÷ sample minutes.
After rate = after earned ÷ the same sample minutes.
Payback = cost ÷ (after rate − baseline rate), only for positive extra rate.
Wait to afford = max(0, cost + reserve − balance) ÷ baseline rate.
Cash after purchase = balance + baseline rate × wait − cost.
Target time = wait + max(0, target − cash after purchase) ÷ after rate.
Saving time = max(0, target − balance) ÷ baseline rate.
A zero rate with a positive shortfall has no finite arrival. Catch-up versus saving = wait + payback. An already funded goal requires no new purchase.
INVENTED EXAMPLE · NOT GAME VALUES
The best cash path changes with the target.
Suppose you have 500 cash, protect 100, earn 100 per 10 minutes and want a balance of 1,000. A costs 100 and earns 150 per 10 minutes; B costs 400 and earns 200 per 10 minutes.
| Path | Payback after purchase | Time to 1,000 | Time to 600 |
|---|---|---|---|
| Keep saving | No purchase | 50 min | 10 min |
| A | 20 min | 40 min | 13.33 min |
| B | 40 min | 45 min | 25 min |
A reaches the larger target first. For a nearby 600-cash goal, saving wins. Buying the option with the largest after-rate is not always the fastest route to the next goal.
If instead you start at 0, A needs 20 minutes to fund its 100-cash cost plus a 100-cash reserve at 10/minute. After purchase, 100 remains; reaching 1,000 at 15/minute takes another 60 minutes, for 80 minutes total.
Use the output as a conditional decision.
Costs and income fields begin blank. Only game-screen-verified data could support built-in game values, and we have not verified paired cash observations. Your current samples or clearly labelled estimates supply the calculations. No accounts, codes, ranks or drop probabilities are requested.
Keep normal operating expenses included in net cash earnings. Enter the one-time investment cost separately; do not subtract it twice. A temporary boost, area change or different crew can invalidate a before/after comparison.
See calculator evidence boundaries, how to measure and local storage behavior.