I think a lot of it has to do with what you want from the detector and how much you are willing to pay to get those specific features. I think, in many cases, a simple but good performing beep and dig detector returns a lot of performance for the cost.Great point.
Comparing a Nokta Invenio at $5000 to the $1600 Manticore would be a much better evaluation with the same result.
One could purchase 3 of the brand new Minelab Manticore's , for the price of just 1 Nokta Invenio.
Makes the Manticore seem like a really great deal.
But again, way to soon to begin comparing brand new technology with old.