It's the "if done right" bit that's so tricky.

So often though the GoodThing doesn't have a clear payoff and another FastThing does.

Sure, but you have to reinvest that money too. And it's a bit misleading to take just the FastThing cost and disregard the GoodThing costs.

For example -- it took 10 days to build a JS prototype, but 10 more years of evolution before it became the dominant Web Development language.