The upgrade that would have cost us money
We ran the numbers on a repair that would have raised a price. The math said no, so we disclosed the flaw instead.
A Leica cold light source came through the bench with one open question: was it worth buying a compatible fiber-optic light guide to upgrade the listing from lamp output unverified to tested working before it shipped? We ran the actual numbers instead of guessing, and the numbers said no.
The decision point
The unit’s lamp cannot even be tested without a specific fiber-optic light guide seated in its socket, a sensor interlock built into the housing. The compatible guide is not a cheap or generic part. Real listings for one that actually fits this model run $88 to $110 rather than the $25 to $40 we had first assumed before checking.
That first assumption is worth admitting to. A cheaper generic fiber-optic guide would have been the easy purchase, and it would have been wrong. This unit’s light-guide socket takes a specific ferrule size that most inexpensive guides on the market do not match, so the first estimate of what the part would cost was simply off, and the real number changed the decision.
The math
Selling the unit body-only, disclosed as untested, nets roughly $137 after the marketplace fee and packaging. Selling it as tested working, at the higher price that claim would justify, nets closer to $214 before subtracting the cost of the guide itself. Subtract the $88 to $110 for the guide and the tested-working path actually nets roughly $33 less than just shipping the unit honestly as-is.
Buying the part to upgrade the claim would have lost money on this specific unit. The math did not support it.
What we did instead
The unit shipped with the honest disclosure: lamp output unverified, because it genuinely was not verified, and the part needed to verify it was not worth buying for this sale. Unverified here does not mean probably broken. It means exactly what it says: we could not test the one function that matters most, and we are telling you that instead of guessing.
What unverified versus tested means for a buyer
A buyer looking at this listing knows precisely what they are getting: everything else about the unit checked out, and the one component we could not verify without spending more than the upgrade was worth is named plainly rather than glossed over. That is a different thing from a listing that simply omits the question.
The alternative would have been to either spend the money and eat the loss quietly, or skip the light guide and claim tested working anyway on the strength of everything else that did check out. Neither of those was on the table. The cheaper option was telling the truth about the one thing we could not confirm.
The honest close
The unit sold afterward for $159.99 against a $150.00 acquisition cost, a closed sale, roughly break-even once marketplace fees are counted. That is not discipline paid off. Spending on the guide would have made an already marginal position worse, not turned it into a win. The right call here was not making money. It was not losing more of it.