Spitflier - on a side note, I am new to CAS also and after putting over 2,000 rounds threw my new guns, my opinion is that your guns must operate properly for you and your capabilities. You don't need a Corvette to drive to church... Tuning a gun shaves thousands of a second off your time. Missing the target costs you 5 sec. Transition between guns on a stage saves 'seconds' off your time. You must make 1,000 modifications to your guns to save 1 sec off your time. See where I'm going with this?
Concentrate on the important things. Try out as many guns as you can to see what you 'need' to be competitive at your level. I bought SASS Rugers because they come with a hammer that fits me. I changed the springs myself. I bought a CAS 1873 because the stock is already modified. The short stroke will help anyone. With a few adjustments, it was smooth operating for a starting shooter.
I bought a used shotgun that someone had modified and I spent countless hours (lots of Dollars if you can't do your own work, which few of us can do) to make it run right. For me, the shotgun was not so important and I knew what I was getting into; barrel separation, lock timing, double discharge problem, improper stock finish, bent firing pins, etc. SO , consider your purchases carefully. A larger investment up front may provide a smoother ride.
There is nothing worse than going to the line with a gun your not sure about...
New vs. Used: if you find a good deal on used, buy the time you need to really go fast you will be ready for a high end gun (if the used one lasts). Then you'll have a 'backup' when things go South with your main guns and have to take a trip to the Smith.