What the engine does
The engine structures the numbers you enter. It does not fetch an automatic valuation, know the true condition of the item or pretend to be a professional opinion. It exposes assumptions and tests whether the decision survives changes in cost and risk.
| Element | Rule |
|---|---|
| Full cost | price + mandatory costs + optional costs + contingency |
| Net cost | full cost − estimated resale value |
| Risk | weighted assessment of condition, seller, documentation and protection |
| Value score | price 55%, safety 35%, condition 10%, adjusted for time pressure |
| Price ceiling | benchmark adjusted for condition, protection, costs and contingency |
Verdict thresholds
“Worth considering” requires a high value score, moderate risk and a total cost not materially above the benchmark. “Negotiate” is the middle case. “Pass or verify further” appears with low value, high risk or a large premium over the benchmark.
How to test sensitivity
Run the analysis three times using optimistic, realistic and cautious repair or resale assumptions. A robust purchase still makes sense in at least two scenarios and does not depend on one uncertain number.