When the premise is "this tool lets you reduce the number of programmers you need from 10 to 2", that's a good premise.
I want to know about any tool that makes programmers five times more effective!
Moreover, we've probably both seen cases where the philosophy was "this tools is expensive, so it *must* be good".
But I've seen a lot more "A thousand dollars is a lot of money" when I see it add 5-10% to a 100K programmer's productivity. Admittedly, it *is* hard to measure productivity, but my general philosophy is that if you *aren't* spending a few percent of an employees salary to enhance their productivity, you should be looking carefully to make sure you're getting the most out of them.
It's amazing how often you see employees losing 30 minutes a day in cumulative 1 minute delays (which frustrates the heck out of them) because spending 2K for a decent computer is out of the question. Far cheaper to lose 15% of the employees productivity and the increased turn-over due to the frustration is just icing on the cheapness cake!
So, with respect to the topic at hand, I strongly believe if you have decent employees, then they can probably tell you what engine will work best for them. And if it costs up front, then you pay it. And no, I don't expect 500% productivity increases. But it doesn't take much of a productivity increase to have the right product pay for itself within the year.