9mm v. 38 super.
if you're just getting started and have tons of 9 brass, i think you'll be happy with a 9 Open gun. And, if the barrel/chamber is worth a crap, you can reload the brass lots of times.
But i will say, the 38 super is flatter/softer, and in the long run, more efficient and fun. The only downside for 38 super is the brass, all other expenses are the same.