We once bought a Mazda demo cause it was the precise car we wanted, and got a screamin' good deal. However, it only had 800 km's on it, not 15,000. That Accord is NOT a "demo" but a used car that just hasn't been titled.
I would probably buy the car for about $26-27K including a Honda extended warranty. Since 2003 used EX-L's seem to be about $24K or so with 20-25K, $26K would be a fair price for the 04.