Going by the chart in the article, if your total workload is 1k cataloged items and your quality threshold is 70%, why wouldn't you just pay $19 to gemini API instead of $500 + time to make a custom fine tune?
The resultant model much cheaper per call and outperforming frontier models. So you'd quickly make your money back at any sort of meaningful scale, continue to pay less from that point on, and have better results. And I think removing a third party dependency is also a benefit in and of itself.