He'll struggle to get a Capri worth having for that budget - they have been appreciating steadily for a few years now. I think he'll need to spend nearer £1500 - £2000 for a halfway tidy 1.6 or 2.0 Capri (2.8 should be over that budget unless it's a bit of a nail)
Look for rot on the sills, strut tops, wings, rear 3/4 "pockets", B-posts, battery tray - pretty much anywhere you'd expect a 70s/80s car to rot really. Mechanically they are pretty much bombproof aside from the Pinto engine which can develop cam issues and a smoking habit when the miles pile up.