That's the problem with "MBA thinking". You can't put a dollar value on R&D. You just can't. Anything you do will be a gross approximation, and because the number is so fuzzy, you'll be encouraged (even subconsciously) to fudge it around to make other things look better, which will undoubtedly lead you to undervalue R&D to the point where it negatively impacts your business, but you have no idea why, because you're solely focused on dollar figures and not what really matters. Y'know, like developing the ability to solve actual customer problems in an exceptional manner. This sort of thing is very difficult to quantify, and any approach that starts from a finance perspective is always going to be sub-optimal at best, but often just flat-out wrong.
I see so many people optimizing the things that are quantifiable at the expense of the things that aren't, when the loss of the qualitative things is what's killing their business. MBA types seem to never get this, and the form of your reply is basically a textbook example of that.