AerBabe, you forgot to mention the lawnmower...
I reckon the PFA route is the way to go. £12k - £15k will buy you a nice Jodel or Aeronca, which will cost you £20-£30 per hour to fly. Hangarage is a bit of a killer down south (think £2k+ per year), so unless you can find a friendly farmer i'd look at a small group - it splits the fixed costs, but availability is still very good. Much cheaper than club hire, and, dare I say it, much more interesting too...