I wouldn't quite make the argument that, if this were a toy, it should be as cheap as a destroid. There would be two toys (Zentraedi soldier AND the Regult... although I suppose the soldier could be sold separately). Really though these are bigger than Destroids and the whole cockpit area is a level of detail and complexity that I'd say exceeds the Destroids. So, I'd be willing to pay more for a Regult than a Destroid... but certainly not 5 times more for an unpainted unassembled model.
I also disagree with the logic that Yamato doesn't have the capacity to build this as a toy (but Bandai does). I would agree that they are choosing to go the model route because there is essentially NO risk there and they appear to be under much tighter budgetary restraints these days. They are making a decision to go this route, Joe Schmoe wouldn't have had a decision to make... resin would be his only option. I'm a little bit bummed I won't be getting a sweet Regult toy but I understand the economics of Yamato's choice and if that's what they feel is prudent then oh well... maybe Bandai will give us Hi-Metal baddies (LONG SHOT).