I wonder why there's always the justification that developers are expensive when it is they that wrote the code that's causing the problem. Having them write the same crap code faster is a totally losing battle.
If you want to do something right, train the developers to write better code, and then make their jobs (and their managers' jobs) depend on it.
As soon as you've accomplished such a thing, you'll find that the cost of developers will actually drop a lot compared to their throughput which no longer requires either functional or performance rework.
Like the old saying goes... "What if we train our developers and they leave"? Better question... "What happens if we don't and they stay?" 😉
Not every business allows for training. Where I work they haven't done any training in decades, or so I'm told. I'm sure where I work isn't the only place that's like this.
I can guarantee that the place you work isn't the only place like that. The training that I'm talking about comes from the DBA during design reviews and peer reviews. Of course, there are a whole lot of places that don't do either one of those... and it usually shows, especially on forums like SSC.