When I began selling musical supplies on eBay back in 1999 one thing that motivated me was horror stories from parents.  Knowing nothing about musical instruments, particularly clarinets, is a real setup to be taken by a scam artist or a fast dollar salesperson who doesn't care a hoot about them.  Having played clarinet for over 47 years (along with other instruments) I knew it wasn't the kind of instrument one could purchase by price tag alone.  Many cheaper instruments that are for sale are not of good enough quality for a beginner or a returning player.  A poor quality instrument will not play in tune with a good tone and will not hold up to the rigors of marching and concert band.  But there are many, many excellent eBay sellers who know what they're doing and have good instruments for a really low price.  For instance, there are several sellers who sell Buffet E-11 Bb clarinets at a good discount.  Some of these are used, so if that's one you are wanting be sure it has been repadded and set up by a professional tech person.  Also, be sure your seller is willing to communicate with you by sending him/her an email to ask a few test questions like: "How old is this instrument?  Do you offer a trial period with refund?"  Be sure your seller will stand behind his/her merchandise.  Also, be sure to check the feedback.  I usually refuse to do business with a clarinet salesperson who has below a 98% positive feedback rating.

Some of my favorite student/intermediate clarinets are: The Buffet B-12 or E-11 (as mentioned above), the Yamaha YCL 34 (which has been replaced by the YCL450) and the Leblanc Cadenza or the new Bliss coming out in July of 2008.  Morrie Backun is Leblanc's new developer and a clarinet guru to top professional clarinetists around the world.  His new line of clarinets is nothing short of amazing.  Dave Kessler of Kessler Music is a respected eBay seller and full dealer of musical instruments.  Check him out. 

There are other clarinets that can be purchased for a good price, but the novice is better off to stay with the top 4 name brands: Buffet, Leblanc, Yamaha and Selmer. 

Tom Ridenour is another great clarinet developer and has a non-wood clarinet called the Lyrique that is a fantastic instrument.  It has a great tone and many professional players are using it for outdoor and indoor studio work.  It sells new for under $1,000.00.  Every once in a while you'll see one on eBay.

For professional clarinetists or students advancing into college work I recommend the Buffet R-13.  This is what I play.  It's a standard around the world and is one that holds its value better than most brands.  You can usually find a good used one on eBay for $1,000.00 to 1,700.00.  New is almost $3,000.00 these days.  I also recommend the Leblanc line of professional instruments, the Backuns and the Opus II and Concerto II.  Leblancs are known for their excellent intonation up and down the scale.

Making a decision about an instrument is difficult.  It's your hard earned money (or someone's).  Take your time.  Compare everything and ask lots of questions.  If there is a store where you can go try some out that would be great.  Once you know what you want come on back to eBay and find a good deal.