Congrats! I have fiddled around with A Fontaine clarinets and also found them to be solid players. They are a "stencil" brand (made by someone else, then branded "A Fontaine" later), and many were made by Couesnon, who was a high quality manufacturer. They tend not to resell for much money (neither A Fontaine nor Couesnon are brands most people remember today), but they can be terrific for doublers, adults returning to the instrument, etc. Just watch your intonation -- it tends to be a little "iffy" depending on the horn and its specifics.
Good luck!
Good luck!