206's are great machines, but you NEED to know its history. They are great to fly, safe, tractors of the sky, but like all of us, are not getting any younger. As we get older, bits start to wear out, and sometimes fall off!! The same with old machinery, so buy the one with the best history, service records, the newest one that one can afford, of the last model that was made. Spensing an extra £50k now will save you £100k down the road. As for an AOC in the UK, do you need one now as with the new EASA ruling from last may, a pilot only has to contribute to the cost of a flight, (£1?) to be legal......who can define the accurate actual cost of a particular flight!!
Good luck finding "that" cheap, good, reliable , safe machine