I don't know if there ever WAS a time when mainstream music stores were knowledgeable about arrangers (at least here in the US). Since the M1, WS's have dominated the market, and low end arrangers are sold as toys for kids at Christmas. High end arrangers, IMO, have ALWAYS been a rare breed, and those that sold them knowledgeably a rarer breed still...
BTW, when a salesman has no knowledge of an unreleased product, you can hardly blame him. His job is to sell EXISTING stock, not to talk people into waiting until a new model eventually gets there (if it ever does). A sale deferred is a sale potentially lost.
It's hard to expect any salesman to educate themselves exhaustively on arrangers (or any other product) when we all too often prove to them that their knowledge is of no value to us. If we can find the product cheaper somewhere else, we'll go there AFTER we have wasted his time, and he gets nothing for his effort.
I see it on this board, all the time. A knowledgeable dealer takes time out of his workday to answer questions, provide information, even be objective about flaws in products he sells. And then someone goes 'yeah, but can anyone tell me if they have found somewhere that sells it for less'
Would YOU bother to take the time when that is a common response? You want it cheap? Educate yourself (and be prepared to take a bath if you get it wrong). If you want qualified advice, technical help, honest forthright dealer opinion?
PAY SOMETHING FOR IT, YOU CHEAP SON OF A B...CH!
You expect to get paid for your 'pro' work. And the better you play and entertain, the more you expect for YOUR work. Why doesn't this extend to salesmen and dealers?