Start with cost per clean, not purchase price
Ask the vendor for the figures you need to build a per-job cost sheet, then calculate the cost of one completed wash: labor minutes multiplied by the loaded hourly rate, plus water, plus energy, plus any detergent or consumables, plus the amortized machine cost over its expected service life. A model that looks 20 percent cheaper on the invoice can end up costing more per job if an operator spends fifteen extra minutes on the same task, because labor is normally the largest single line item in a wash bay.
Write the calculation on one page and require every shortlisted supplier to supply the same inputs. Where a specification is missing, ask for it in writing rather than estimating it yourself. On the PowerDe Fixed Steam Cleaning Machine PowerDe HW02 detail page, for example, the published parameters include 6 kW heating power, 160
