I would not have accepted 1/2 the cost for being 0% at fault. With lawyer friends so readily available, why wouldn't you have just taken him to small claims court?
At the end of the day, you got something from him and that's better than nothing. As much as I think he should have given you 100% for the phone and as much as we can all say what we would have done, the decision is ultimately yours.
He only..gave you...50%... half...? Well, you should've chopped off his left testicle to see how HE likes only having "half" of what he SHOULD have. because you SHOULD have 100% of the value from him.
If you're happy with the outcome that's all that matters. Personally I wouldn't be but if you pushed for the full price you may not have gotten anything from the idiot. People sometimes suck.
$400 for a wallet??? WTF
Should had one of your lawyer friends send him an official letter about taking him to court. Bet he would of coughed up the cash then.