I'd say still a little to high. They are good reliable guns that are built like tanks, long DA trigger pull though. I traded mine off for a smaller carry gun but would by one in the future just because how rugged they are. All in all if he lowers to $375 I'd buy.
I had one, bought it used with unknown round count, very clean though. heavy trigger and liked to jam ALOT. maybe crap ammo, user error, the wind... all I know is that I got rid of it asap. This was 10 years ago, it was fairly new. I have not followed Ruger since. I have heard similar stories from friends that had ruger autos of the same era. I hope they fixed it.
If memory serves me right, my wife had the DC version. She had zero FTFs and it was one of her favorites. All the usuals apply: clean thoroughly when you first get it, check your magazines for flaws, see which ammo works for you. They are tough and durable. With the extras, $400 doesn't sound too unreasonable to me.
My first gun 12 years ago was a P89 which I regret selling. When things improve I may look into one just for the nostalgia. Super reliable after several thousand rounds. Only had issues with some crappy reloads. It ate everything else I threw at it.