The economics of building an aeroplane are that, with perhaps the exception of the engine, there's virtually no difference in the cost of building a C152 and a C172. They are about the same, shape, materials, and most importantly number of parts. Take the back seats, seatbelts, etc. out of the C172 and you'll probably break even.
The real economics are in running costs - and a huge part of that is fuel burn.
Let's say you buy a new aeroplane at say £120k (class and type irrelevant) and amortise that on a 10 year loan - with some interest, say £15k.pa.
Now fly it about 200 hours per year, with the major running cost being fuel.
C172: say 35 litres/hr at £2/litre of AVGAS, that's £14k.pa
C152: say 25 litres/hr at £2/litre of AVGAS, that's £10k.pa
C42: say 20 litres/hr at £1.40/litre of MOGAS, that's £5.6k.pa
And all of that saving really comes down to two things - the aeroplane weight, which with current technology be roughly proportional to the fuel burn, and the tax regime of the fuel it's burning.
Now put it up to school useage of 500hrs.pa, and the purchase cost of the aeroplane is relatively irrelevant - it's all massively dominated by fuel.
Comparing these three aeroplanes again - well the load on the structure is directly proportional to the weight. And so the (very rough numbers) 1 tonne C172 needs to have twice the amount of structure as the half tonne C42. So it needs half the amount of structure in the undercarriage, and half the amount of structure in the wing. The C152 is about halfway between.
So to anybody who is used to the appearance of the Cessnas, the C42 looks flimsy and under-engineered. In reality, it's designed to virtually identical structural requirements as the other two aeroplanes, and thus just about as easy, or difficult, to break. Because those requirements are phrased in terms of g-loadings.
But that low weight (and apparent flimsiness) is what keeps the running costs low.
In that light, the Skycatcher would have offered significant advantages over both the C172 and C152, including economic ones. But, not as great as the advantage of a C42 which is lighter again and runs on MOGAS. That the C42 is 2/3 the price to buy is another bonus, but when you analyse it, a relatively small one.
G