How the cost of waiting is calculated

The formula

Cost of waiting = resale decay + repairs during the wait + price increase

Resale decay is today's resale value minus the value you expect after the wait. Repairs are your annual repair spend scaled to the waiting period. Price increase is the next model's launch price minus today's price, counted only if it rises.

Per month = total / months waited. This is the number to compare against what the upgrade is worth to you.

A worked example

Current machine sells for 650 today and about 380 in six months. Repairs run 120 a year. The next model is expected at 2099, against 1999 today.

• Resale decay: 270.
• Repairs for six months: 60.
• Price increase: 100.
• Total: 430 over six months, about 72 per month.

So waiting six months is roughly a 72 per month subscription for the privilege of seeing reviews first. Whether that is worth it depends entirely on how much the next model matters for your work, which is the one input the calculator cannot supply.

The asymmetry most people miss

Resale decay is not linear. The first year of a machine's life carries the steepest drop, so a machine that is already two years old decays more slowly in absolute terms than a new one would. That cuts both ways: waiting on an old machine is cheaper than waiting on a new one.

When the answer is obvious

If resale decay alone exceeds the price difference between the two models, waiting is expensive by construction. If the machine is worth almost nothing and needs no repairs, waiting is nearly free and the decision should be made on capability.

Sensitivity

Change one input at a time. If doubling the repair estimate does not change your verdict, repairs are not your decision. If moving the wait from three to six months barely changes the total, decay is not your decision either, and you are choosing on features rather than money. That is a fine way to choose, as long as it is deliberate.