Buying lose diamonds -- reasonable cost range to get them set locally?

I wanted to buy some loose round and Ascher diamonds to get made into custom earrings (6 prong martini and bezel set, respectively). Can anyone provide some data points on what to expect in terms of pricing for having a local jeweler set them? (Thinking 14-18K yellow gold or maybe WG). It seems Luvansh charges about $400 for 18K YG setting, but their "automated" setting options are limited and would also render the stones non-returnable. I would like a chance to view the stones before committing to them. Is $400 a good reference point to set a pair of diamond earrings, or should I expect more or less of a charge from someone local? And are there specific questions I should ask a jeweler?