>I’m not very good at estimating timelines, so I gave a (very) rough estimate of 2 to 4 months. A reply affirming that that sounded reasonable, with an estimation of 300 to 400 hours of work, with a price tag of $10,000 was what I got back (assuming the project didn’t run seriously overtime).

The author of the article gave an estimate of hundreds of hours across 2 to 4 months and Analogue's valuation of that time was $10k - for an expert in the domain working in software. That number is an insult. Even doubled it's quite bad.