Why the cash model should remain narrow
Transmute guarantees its stated gold, but the sacrificed creep had a bounty. The cash layer therefore counts only incremental gold above that alternative.
Attack speed and Madstone can create real game value, but it depends on hero, neutral target and match state. One universal exchange rate would turn a useful model into attractive fiction.
What a 35-gold sensitivity shows
A minute-12 purchase with a minute-38 finish gets 18 uses in the cash-only model: 2,160 incremental gold, still 40 below the item price. Payback would arrive near minute 39.
If the user values Madstone and attack speed together at 35 additional gold per use, incremental value becomes 155. Fifteen uses are enough and break-even moves to roughly minute 33.
Keep sensitivity from becoming self-justification
Enter other value before viewing the answer and state what it represents. After the match, test whether attack speed changed farm or fighting and whether the Madstone option produced actual utility.
If the estimate exists only to force positive ROI, keep the cash baseline at zero. The model should challenge the purchase, not rationalize it.
Replace the baseline with your inputs and get an answer for your scenario.
Data note. Every numeric example is a transparent baseline scenario. It is not presented as official publisher data and can be recalculated in the linked tool.