Just my opinion based on past experience,
Compared to industrial type lifts rough terrain lifts (commonly used on construction sites) accumulate less total operating hours in a day. They tend to sit a lot a wait for work.- like lift a load of trusses, roof materials, sheet rock.. Maybe an hour a day.
But what is more important is because they commonly are working "off road" and are operated in dirt & muddy conditions is the condition of the unit & maintenance, repair history on the unit. Have someone familiar & technically competent with rough terrain lifts inspect it & give you a condition report.
Last point, hour meter readings are often miss leading - they are often replaced, disconnected, broken. But excess wear on mast sections or steering components, trans slip, etc can't be hidden easily.