D15B 1.5l SOHC VTEC
If you can confirm that that is the right engine, take a closer look at rust spots. Check the rockers behind the plastic covering. Knock on the metal around the quarter panels to check for bondo.
If it's got more rust or bondo, I'd say $1000 or less. Otherwise, I still wouldn't go over $1500k for even a nice 400k mile unrestored, engine swapped Civic.
Coming from a guy who spent three years with an unknown-mile, rusty, bondo'd, engine swapped, unrestored Civic.