I am keeping half an eye on exactly the same thing, but I would want 700m+.
Money would not be a problem (within a reasonable budget, on the scale of agricultural land costs) since I am primarily after security from property sharks closing the local airfield, and weekend/weekday-accessible hangarage in the form of a shed of some sort.
I reckon that setting up covertly first, with low usage (say once a week) for a few months, might be a good idea. Obviously a field which doesn't have houses near is preferable; even in the most densely populated UK countryside there are loads of such fields.
The #1 problem I see is how does one zero in on one. It's easy to just fly around, with a GPS and marking waypoints over interesting sites. There is a vast number of suitable sites which have the requires attributes
- orientation to prevailing winds
- flatness
- road access (somewhere to park a car, and enough access for a trailer if there is a major issue that prevents it being flown out)
- lack of houses on the approach
- a barn nearby
- who owns the field beyond this one (if same person, OK, but if somebody else then he might deliberately plant some trees at the end of your strip...)
but how does one contact the owner? Presumably one can get the title details from the Land Reg, but that will work only if the land has been sold since the 1970s. A lot of farmland has not changed ownership for much longer than that.
This could be a very long slow process.