I haven't a clue really, but around here we pay £35/acre-ish for lots of 100 acres or so of rough grazing, for which we have to do all maintenance. It would need to be good grass and mowable to be more than £50/acre.
If renting is like buying, small plots cost proprotionately a lot more than large.
If you are fencing it and repairing the dykes then 1p sounds about right!! seriously, thats worth far more than a year's rent.
Hmmm ... depending on what they want to do with the land next year, if it will have had pigs and goats on it! If they want to cultivate it, pigs would be worth their weight in ...
but if they want it as pasture then probably the pigs would leave it needing reseeding (albeit on a well-fertilised topsoil.)
Hope that helps - even if only a little!