For accessories try to find the manufacturer/distributor ( i.e., Corbin, RDL, MC enterprises, etc.etc.ect.)to cut out all middlemen and get the best recourse for warranties. For spare parts buy only genuine Yamaha parts from any of the many sources on the internet. Prices may vary, but not by much if you use OEM parts. In my experience my selling dealer will always set up an account for me for 15-20% discount of anything I buy. Makes most of the internet shopping unnecessary.
YMMV