I said competing markets. Data from competing markets is always relevant.
Data from competing markets is relevant, and the first thing I would have done is searched for another condo in competing area.
In this case, there are none, all he has are the building sales themselves. There was one high sale at $386k and change, the others are lower prices.. We know nothing turns out about the other sales. Are they all the same size and layout as subject? Different sizes, what about floor height, views, and how upgraded? What if the highest price sale was an older dated sale, and the lower priced ones newer contract dates? We know nothing about nothing...
If highest price sale was smaller, or on a lower floor, or inferior upgrades, would lend support for subject value being even more $ than that highest price unit. But again, we don't know..
None of us asked these questions early on, we got too involved with debating with each other and our own egos. And now unless OP returns with information about the sales, we will never know.
I suppose the moral of this story might be to be a bit cautious about giving, or receiving advice when the most important information is lacking.