I think you underestimate the cost of adding the extra flash memory, Beaky. It's not just the cost of adding the raw component itself, but the cost of redesigning the main board in it's entirety... it's the cost of redesigning the chips, logic board and a host of other things. There's a reason why Yamaha can keep trotting out quite improved arrangers at little more than the cost of the previous models... It is because they are using essentially the SAME hardware architecture, and the majority of the improvements are due to upgraded sounds and OS features.

But once you start to add in hardware components that are main board related (unlike, say, a better display, a separate component), you vastly increase the cost of production. No the flash memory itself is cheap, but the cost of incorporating it into a new design is the TRUE cost.