ok, as someone who has imported for years I have a little experience here, the variable as tremendous depending on where the fish come from, ie. Asian, most expensive, Colombia, not to bad (is close to us), Uruguay, most expensive in this hemisphere, different parts of Brazil charge different prices, also depends on how many fish that certain supplier put into a box, I got a 25" plus Adonis Pleco a few years ago, I did not sell it for near the top end of your scale. I think I sold him for $175 plus shipping, and made money.
Thanks for chiming in Ken. Like I said, I don't have many of the larger fish data points. This can skew the data. If I remove the discus outliers (5" at $150) it increases my R-squared to about .82 and drops the cost of a 22" fish to $400. If I had more data it would be more accurate for sure! Any way you'd chime in on what you'd think it would cost to import a 20"+ cichlid?