Compares buying the tool against hiring it, for the number of jobs you actually have.
Formula
buy = tool price + consumables per job x jobs - resale value; hire = hire rate per day x days per job x jobs; break-even jobs = (tool price - resale) / (hire cost per job - consumables per job)
Assumptions
Delivery, deposit and insurance on a hire are not included unless added to the hire rate.
Your own time is not costed.
Limits
Hire rates and deposits differ by depot and season; check a real quotation before deciding.