What you should buy depends on the type tobacco your going to smoke in it. Different pipes smoke different blends... differently.
If you're not sure what you will smoke in it I would buy a nice pre-smoked Castello. I own a lot of them, some I've had for over 40 years. They smoke any blend well, especailly English and Balkan blends, and I've never encountered a bad one.
Ok, here's a chance for all you guys to beat me up... I'll never understand all the hype about Petersons, They look good and are nicely made but in my experience thay are nothing special when it comes to smoking qualities. I think they're the most overrated pipe on the market and the socalled "system" is a joke... it does nothing for most smokers. The only way I can see that the system could possibly do any good is if you are like some European smokers, especailly the Danes, who smoke a lot of blends that are extremely heavily cased. Those blends smoke so wet that they probably do drip goo into the well. But for most of us this isn't the case.