Genghis, I can honestly say that I am stunned to be expressing an opinion that is at odds with yours.
You know how much I value your input to this forum, based on your extensive experience of GA, but I must point out a little flaw in your last post.
I on the other hand, am always surprised when anybody at-all agrees with me.
There are swings and roundabouts here of course. Yes, you're quite right that an NPPL holder doesn't need to pay for a class 2 medical.
On the other hand - I'm just helping out a husband and wife who have jointly bought a microlight. The wife who holds an EASA PPL will only need differences training. The husband, who for historical reasons holds an NPPL(SSEA), will need a microlight skill test - so for him, in this instance, having an NPPL will be much more expensive as differences training doesn't require the instructor to train somebody to pass a skill test again, nor is there the cost of a skill test.
But, back to the cost of learning again. For an ab-initio student over, say, 30 - it's unlikely that anybody will get from zero to light aircraft pilot under 45 hours, and so the two licences will (medical aside) cost the same to obtain for all reasonable purposes.
chipsto - you've stumbled in my opinion upon one of the major advantages of going with microlights, which is the sheer level of enthusiasm for their flying you'll find at all levels. Don't lose that! The Eurostar's a nice training aeroplane which I'm sure you'll enjoy as well and much newer and shinier, with at least as good performance, as most light training aeroplanes you're likely to come across.
For what it's worth, I started on microlights, flew those for half a dozen years, then did a light aircraft licence and carried on flying both. That's worked for me so far. Yesterday I flew an X'Air, this afternoon I shall fly an AA5, and actually - the X'Air is more fun, as well as costing a fraction to run (just goes rather slower!).
G