I would only do something like this in a very very narrow case where I was a VERY small amount from the next status level and the next segment was quite expensive. For example, if I was 40 PQP from Silver (or 1k), and I was about fly a $5000 one way from IAH-SYD in paid J. That would net me an extra 10000 RDMs (or 5000 for Gold/Platinum). In this case, if I had time to do so, I would push an extra $1000 of spend onto my Quest card, with an opportunity cost of 500 Chase Ultimate Rewards points that are worth $10 or so. That would be an easy call.

If I was instead 200 PQPs away, and didn't have time or spend needs to do it via card, I could probably find a way to buy the points using Award Accelerator for about $300. That would also come with around 3000 RDMs. So 10000+3000=13000 RDMs for $300. I think that's a pretty close call. It's 1/8th of a saver award I like to book (100k IN to Australia) --- and I'd value that at more than $2400 so I'd strongly consider it. But as jsloan values them above, they're only worth $130-195, so not worth it.

But you have to do the math for both the buy/no-buy scenarios (at different points in time) and decide your own valuation of the RDMs. If you're checking bags and don't otherwise have access to free checked bags, that should also bump you up significantly. Also, in my example above, if I was flying economy (which would never happen on that route), the free E+ can be factored in as well.