That's Odd...
I could have sworn I ALWAYS ended up paying more for renting something than when I just bought it outright... Pah. Must just be my imagination. And maybe it's just my lack of business acumen, but to me, if you spend $100k... $100k is SPENT. When you say, "We're not spending it on internal capital resources anymore, these are now operating costs, so they don't count," to me it seems like you're in total denial that you've actually spent anything (except to the people you've paid the money to).
Then taking the 'savings' and spending it in other places, is like spending money you don't have! Why not just get the extra money and throw it at product development ANYWAY?
But then, I live in a tiny little house because I've never believed in spending make-believe money that I don't actually HAVE.