Roof repair
A repair on a roof with ten years left is maintenance. The same repair on a roof with two years left is a deposit on a replacement you are going to buy anyway.
The question is age, not the leak
A single damaged area on a roof that is otherwise sound and has years of life left is a repair, and it should be priced like one. The same damage on a roof where shingles are curling, granules are collecting in the gutters and the field looks uniformly worn is the first of several calls.
Any assessment worth paying for should tell you which situation you are in, and should be able to say why — the state of the granules, the flexibility of the shingle, the condition of the decking where it can be seen from the attic.
What a real repair includes
Finding where the water actually enters, which is frequently uphill from where it shows inside. Removing the affected shingles rather than sealing over them. Checking and replacing the underlayment underneath. Re-flashing if the leak is at a transition, which it usually is. And matching the existing shingle closely enough that the repair is not the first thing a buyer notices.
The patch-over-patch trap
Roofs on rental property and roofs on houses that have changed hands often carry a history of sealant applied over sealant. Each application buys a season and hides the underlying condition, and by the time the roof comes off, the decking beneath has frequently been wet for years. A roof with visible tar patches at several points is telling you something about how it has been maintained.