If the 10G serial number is in the range Z6835 through A1200, grab it. It's one of relatively few that werre customized by Ralph Morgan to play like Anthony Gigliotti's clarinet. See http://test.woodwind.org/clarinet/BBoard/read.html?f=1&i=199692&t=199692. Otherwise, you should play it before buying, or get it only with an ironclad agreement in writing that you may return it for a full refund for any reason, or for no reason. In particular, you should check the intonation very carefully.
Buffets vary greatly. Again, you must play one before buying or have a return guarantee.