Given the much larger volume of a toy released by Hasbro vs the TakaraTomy version, I'd say Hasbro pays for the majority of Research and Development cost. With the exception of a few Japanese only moulds here and there, Hasbro would be the one ordering the development of the majority of toy moulds anyway, and TakaraTomy probably gives them a discount for the R&D cost with the agreement that they are allowed to use the same moulds to release toys in Japan and Asia. This could possibly be a reason why TakaraTomy can afford to have different paint apps and chrome on their version.