Consider the pots most companies use Alpha Brand average price 50 cents to $1 depending where you buy and how many.
Count the amount of pots on your Tesoro, x that by the $$ above, get your total.
Now use better pots precision, much nicer feel better adjustments.
Average cost depending upon manufacturer average $10-20 each. And up to $50 each. Again Count the amount of pots on your Tesoro, x that by $10-20, get your total.
Plus Tesoro has to add their profits onto the cost of the pots.
The average person couldn't, wouldn't notice the difference in pot feel and or see much performance difference on a typical detector. In that case wouldn't be cost effective to use the expensive parts.
Keeps the final product cost way down as well by using Alpha brand.
Just have to remember when buying a detector its consumer grade device, you not getting a military, NASA grade device.
So Tesoro and the rest are building to a consumer grade standard at prices folks can afford.