Thank you for the site with the seeds on. Having the calculator I had the urge to check the price at 2gram for £1.25 + 1.77pp it equates to £1510 a kilo. Just out of interest (the price is reasonable enough, for seeds.)
I do appreciate Jasper Carrot's humour and did not make a reference to that posting.
After further investigation and discussion elsewhere I can add:-
The plant is being used by gardeners on a temporary basis, to evacuate moles. Once the mole has gone, they can simply lift the plant(s) or even chop it off level with the ground, once the purpose has been served.
The method I was shown was to have several plants and keep placing one over the newest mole run, every time the mole moves until the mole has gone elsewhere. (Probably next door).
Seeing the runs myself the mole moved about 10 foot away from the roots each time in a Northerly direction.
I can not say if the mole had every intention of making that journey without the plant being there. But the person who showed me, said that this was the normal process when using a 'mole plant'.
The plant is a weed (or wild flower depending on how one defines these things) It needs to be treated with respect, it is poison, (was once used as a purge), the sap can cause skin problems (rash) and it may even irritate asthma. Being aware of this some may choose not to grow it at all. Whilst others will happily wear rubber gloves and use it the plant just to shift pests which may have been causing annoyance for years.
Thank you every one for your kind help with this, I will certainly report back on my findings and if any one else does a test it will be interesting to hear from them too.