Since magazine builds were brought up, here's one to ponder (and we all know how accurate magazine build dyno numbers are...):
1970 340 High Performance Mill Dyno - Mopar Muscle Magazine
Just like
@273 said above, this build is pretty basic and I'm pretty sure it would qualify as being less than $1,500 - cam, lifters, valve springs, retainers, intake. I'm not counting the carb, headers, ignition, since none of those things have been mentioned yet. Hell, you'd probably have money left over for beer. Now, let's put this up against the mighty $3k 318.