Fleet Flyer
As for cost, you can have a very similar aeroplane to mine, a taildragger Cessna 140 on a permit or a C150 on a CofA. Their construction is very similar if you get a metal winged 140. The 140 will have the same 0-200 engine and will achieve the same numbers. However the 140 will cost you £300 for the annual permit renewal whereas the 150 will cost you £5K and upwards for its annual. This is assuming neither need any work doing. If the 140 needs work and you're handy with the spanners then you can do many things yourself. On the CofA machine you can change the oil and that's about it, everything else is at £££££££ rates from certified engineers.
Sorry to be pedantic but to clarify: in the UK there are Cessna 120s on LAA Permits, but no Cessna 140s which are all on CofA. And as things stand, no more Cessna 120s can be added to the permit fleet.