Hi Fenster,
Great advice from everyone. Here's what I have to say about ebay.
If you're starting out, don't buy anything for a few months, just watch auctions. Follow auctions of makers or types of pipes that interest you. Get to know prices. Sure some really enticing opportunities will come and go, but there will always be more. In the long run, knowing the market will benefit you more than will any single auction. There's nothing more important than research.
One good research tool on ebay is its advanced search. Just to the right of the search button there's a tiny "advanced" button. You can use this option to look at completed auctions and see what kinds of prices pipes are going for and what kind of condition those pipes are in.
Great deals are rare, but good one's can be found.
Expect the unexpected when it comes to buying something that you can't actually hold in your hand before you buy it. If you have questions, contact the seller. If the seller doesn't respond, walk away. Never bid on a pipe that doesn't have clear pictures, especially of the bowl, rim, and button. If you want more pictures, ask the seller to provide them. If the seller says no, walk away. Never bid on a "no return" auction unless you're willing to live with the result.
Don't be too impressed with a seller's 100% rating. A couple of the biggest crooks I've encountered on ebay had 100% ratings. Read the feedback about the seller, seriously, read it. I learned that one the hard way.
Did I mention research? Oh, and did I mention research?
Do not get emotionally involved. Decide how much you are willing to pay and STICK WITH THAT! Only idiots get into duels. They're fun to watch, but that's about it. Did I mention research?
You can find good deals on ebay. And once in a long, long, while you can find a great deal. But you can also find lots of very bad deals. Research, knowledge, patience and prudence can help you reduce your exposure to bad deals.
There's a sucker born every minute. You don't have to be one of them.