I was able to get a complete M-body left rail from a local picking yard for $150. They even cut the thing out for me. It was so clean I ate my lunch off of it.
I have frame rails in stock, a friend's shop and a welder. But the rest of the car was 100 lbs of unhardened bondo.
Then I was willing to pull parts, but the front 2 doors were toast too.
Not worth $300 and a $300 ride, plus government fees.
I can buy a lot nicer for that money.