Short answer
Comparing attachments by purchase price is like comparing two beams of different lengths by weight. The right unit is cost per hour, and it has four components: depreciation (price paid less resale value), wear parts, maintenance and downtime. Add those four and the price difference between two attachments usually drops to second place, because wear parts and downtime repeat every year while the price difference is paid once. This guide does not give you a figure; it gives you the method for building your own.
The four components
Add the four and divide by the hours the attachment actually worked in that period. The divisor matters: the attachment’s hours, not the carrier’s.
- Depreciation: purchase price less what you will get when you dispose of it. Where a known make holds its second hand value, depreciation shrinks, and that gives back part of the price difference paid on day one.
- Wear parts: tool, bushings, seals, retaining pin and whatever else the model uses. This repeats every year and is usually where the real difference between two attachments is made.
- Maintenance: scheduled service, grease, and a share of oil and filters. The extra maintenance the attachment loads onto the machine belongs here too.
- Downtime: the machine and the crew standing because the attachment is not working. This is the largest component and the most consistently underestimated.
Why a price difference closes quickly
A price difference is one off and paid on day one. Wear parts and downtime repeat every year. So a reasonable difference in tool and bushing life can overtake a difference in purchase price within a few years.
The same logic runs the other way: an expensive attachment that gives no advantage in wear parts or downtime does not repay its price. A brand on its own is not a guarantee; what repays is part life, part availability and service reach.
So the decision is not between price and brand but among the four components. The questions to ask before buying exist precisely to make those four visible.
Counting the downtime component
Downtime is the component most often left out on site, because nobody invoices it. But it is real: when the attachment stops, the machine stops, the operator stops, and usually part of the crew waits too.
Working it out is simple: multiply the hourly cost of the idle machine and crew by the hours lost to the attachment. In most firms that number comes out as a multiple of the part price.
What really drives downtime is not the price of the part but its availability. An expensive part in stock is cheaper than a cheap part waited on for three weeks. We covered this separately in the downtime guide.
We print no figure here, because the figure is yours
Cost per hour depends on your material, how hard you work, your crew cost and the service reach in your region. A number offered as an industry average does not improve your decision, it only gives false confidence. The method is here; the numbers come from your own records.
Do and don’t
Do
- Compare on cost per hour, not on purchase price.
- Use the attachment’s working hours as the divisor; carrier hours break the calculation.
- Work out the wear parts component annually; you pay it every year, not once.
- Cost downtime as machine plus crew.
- Treat the stock position on critical parts as a cost item; what belongs on site is a subject of its own.
Don't
- Do not compare two attachments by price tag alone.
- Do not calculate depreciation without allowing for resale value.
- Do not leave downtime out as "it happens anyway".
- Do not treat a cheap wear part as an advantage on its own; a short-lived part costs more, more often.
- Do not build the calculation on general figures you have heard instead of your own records.
What to record to build the calculation
Kept for a year, those five turn the next attachment decision from an argument into a calculation. The comparison is no longer between two quotations but between your own history and a new quotation, and that is far more reliable.
- The attachment’s working hours. Where there is no measurement, shift count and an estimated proportion.
- Every wear part replaced: date, part name, price.
- Every standstill: date, reason, how many hours, and which part was being waited on.
- Maintenance items: service, grease, and the filter share.
- The disposal value at the point of sale; that figure feeds the next purchase decision directly.