Jayteeto
You can get a half hour trial flight for approx £40 and this will be enough to see if its for you.
The good bits:
The view and sense of freedom is unrivalled
They are really chuckable
They can land in 75m and take of in 150m
Can be kept in the garage
Very cheap flying
Virtually no depreciation on entry level machines
Bad bits:
Tossed around by mid day summer thermals
Very little luggage space, especially if two up
Headwinds will affect range/ground speed
Not accepted at some snobby airfields
I worked the BMAA stand at Fly, Earls Court and lots of people, from PPLs to long haul Captains, came over to chat for the same reasons that you have posted. They wanted some exitement.
There are several Captain and First Officer pilots that have taken up microlights. One of the last 3 Concorde pilots flies a flexwing.
You can go touring in them, but its all about the journey, rather than the arrival.
For the cheapest outlay, look for something like a Pegasus XL with a 447 or 462 engine. They can be picked up for less than £3k. Machines like the Q and Alpha are the next step up and are around the £5k mark. The Blade and Quantum, with 582 or 912 four stroke are £10-£17k with a couple of hundred hours on them.
The 582 is a bit juicy, but all other engines will cruise at 10 litres per hour or less. The 462 will cruise at around 7lph, one up.
Its impossible to comment on hours required for conversion. Some do it in 5, some take 20. Lessons are approx £70-£85ph dual.
Useful links:
BMAA official website
A good microlight club website - great stories