Wow, that must be nice! C'mon, share now...
A guy once told me: "Spend your money while you have it, because when you get older...you won't have any."
Why would you need to 'disable' the on-board flash? If you don't want to use it, then just don't use it. It's not automatic (unless you shoot in the stupid green box mode).As for the on board Flash...I use a plug for the hot shoe that i took off a Nikon.....it disables the onboard flash....Kind of tricks the camera into thinking it has a flash on it....This way I never have to worry about being a flasher...IMO