These are of course ' guestimates ' based on sparse information.
I think one could say that the figure was entirely a "guestimate ".
It may be almost impossible to quantify because much training is undertaken by small firms, but it should be possible to provide a guestimate.
I do not believe that any of them are likely to be right because they are all pure "guestimates".
The "guestimate" may sometimes favour the seller and sometimes favour the buyer, and farmers ask that they should be paid for exactly what they sell.
Today, 17 years later, my guestimate is that on average the agricultural value of the land has decreased from £2,500 to £1,500.
I have indicated that it was clearly a "guestimate".
It is "guestimated" that in the 2020s it will be 10 billion or even more unless action is taken.