Ahhhh...well you see there are different ways of looking at things.
The ancient esp machine may well be worth very little money if anything, but the grinder is always worth atleast the current replacement cost of a new one.....
For example. When someone comes to my humble business premises and wants to buy a used commercial grinder, the lowest we ever quote is the replacement cost (to us) of a new grinder! You see if we sell a used grinder from our fleet...we have to replace it. Therefore to us, it isnt worth selling the old grinder for any less than its replacement cost! Commercial grinders virtually last forever, and a 15 year old grinder does no less than a brand new one as long as the fixtures and fittings are maintained in good condition.
Certainly, the old grinder will be worth more than the machine.....old grinders you/we can use, old machines go to the tip!
Horses for courses!