The YCL 20 was the previous model until the YCL 250 came out. You can usually find one on Ebay (a YCL 20 or YCL 250) for a reasonable price($200-250) Look for one that has been serviced and is ready to play with good pads and corks. I purchased a mint YCL 20 model for my son which had been serviced and refurbished and looked and played like a new one. Hope this helps.
What does the clarinet teacher or band director say? He/She can often advise you what would be a good choice and investment to make. The other question is what your budget is and getting the best bang (or toot) for your buck.