All depends on your idea of self worth if you are porting them yourself. For me it works out to about $700 cheaper for the iron but you lose any idea of using quench and the weight loss of aluminum. Most guys can do a little good, or a lot of damage, and that's once you've gotten the core heads up to snuff in terms of machining and parts. In terms of my builds... To do a set of cast irons that will flow around 245-250 at .500 I'm looking at somewhere close to $1400 including parts and $250 for my porting. To have a set of LA type RPMs ready to bolt on is about $2100. The cheapest iron heads I've seen are Brian's (OU812 here and Moparts) RHS Magnums. But then I still have to ship accross country so there's little bonus for me to get them.