The prices have gone up a bit. Chances are if the plating is worn the pads may be worn also. Used clarinets do not improve with age. You have to also check the condition of the wood. Are the keys nickel plated or Silver plated.. Silver is worth more. The LL was a professional clarinet, the Esprit and Sonata are intermediate clarinets worth much less. I wouldn't pay more than $700 for the LL because they always need some adjustment and if the plating is worn, the key rods might be wornI bought mine off of eBay about 7 years ago for around $450. Looking on eBay, they seem to be going for $600 - $700 US.
I found this post on another board: