Why there is no single number
A prebuy inspection is not a regulated inspection with a defined scope. It is a buyer-directed evaluation, and the cost tracks the scope. Two shops looking at the same airframe can quote very different numbers because they are proposing different work.
The main cost drivers
Aircraft class. A single-engine piston is not a cabin-class turboprop, and neither is a light jet. Access, inspection panels, borescope reach, and required equipment scale with complexity.
Engine and propeller. Compression checks, borescopes, oil analysis, filter cuts, and gearbox or reduction drive inspections add labor. Twin-engine aircraft double this line item.
Records depth. A clean, complete logbook set with recent digital scans reviews faster than a stack of loose entries with gaps and unreadable stamps. Records depth is often the largest source of hidden hours.
Location and travel. Ferrying the aircraft to a buyer-selected shop, or sending an inspector to the aircraft, adds real cost. So does hangar rental for the inspection window.
Shop rate and geography. Labor rates vary by region and specialization. A type-experienced shop usually costs more per hour and produces a better inspection.
What a physical prebuy typically includes
At minimum: a documented walk-around, control-surface and rigging check, engine compression and borescope, oil and filter inspection, a records review sufficient to confirm airworthiness status, and a written findings list. Optional adds include a test flight, avionics functional check, gear swing, and detailed corrosion mapping.
Where records work changes the math
A records pre-screen is done before the aircraft moves. It identifies AD gaps, missing 337s, damage history, engine time anomalies, and STC continuity issues on paper. If a fatal flaw is visible in the records, the buyer walks before paying for travel, hangar time, and inspection labor.
When the records pre-screen passes, the physical prebuy runs more efficiently because the mechanic has a targeted list of areas to open, verify, and photograph. Fewer surprises means fewer open-ended hours.
Questions to ask before you commit
What is the labor estimate in hours, and what is the shop rate? What is explicitly included, and what is quoted separately? Who reviews the logbooks, and how deep does that review go? Who owns the written report, and does it include photographs and references?
Related work
For a plain-language comparison of the terms, see Prebuy vs pre-purchase inspection. For the buyer-side workflow we support, see the pre-purchase inspection service.