Hi,
my local store only keeps one type of top of the line arrangers inhouse the Korg series (and some of the really cheap toy like yamahas). In the keyboard line they sell mainly workstations & synths. They can get other brands of arrangers in, but I really don't think they bother stocking them because they don't have the time to spend or the staff to help customers , once they buy them.
Some of the arrangers are quite a learning curve and the manuals at times are fairly daunting. I, for some bizzare reason , loved reading them. As someone else said, customers find it easier to ring up and ask a heap of questions, instead of trying to find the answers in the manual.
Actually years back, I used to be a bit involved with the local store. They used to pay me to do a one on one start up lesson, on the basics their new workstation or keyboard. In an hour or so, we were pretty much able to cover most of the functions that were important to the individual ( including looking up functions in the manual) Any questions they had after that, I was happy to personally take a call. Used to rarely get a call back, as they knew where to find the answers in the manual for themselves. Actually, it wouldn't have worried me if I'd had lots of calls, as I really enjoyed chatting and trying to help people. Used to give me a great sense of satisfaction, knowing I'd helped someone.

best wishes
Rikki