N2OH & List
Casting is one of the cheapest process in the manufacturing industry. It has been used extensively since the 13th century, and hugely exploited in Victorian times. Parts were cast so that they avoided a whole lot of extra machining.
Cast iron is virtually the cheapest metal on earth (the planet's made of it FFS!).
If you want to reduce the cost of the Listeroid, you have to either reduce the material cost, reduce the number of machining operations, reduce the labout costs or make more of them.
Since there are about 15 manufacturers in India, although this makes for healthy competition, it means that 10 companies are wasting their time producing crap that just won't sell to the West.
The way to make a cheaper Listeroid is to consolidate manufacture to perhaps 5 large manufacturers, invest in new tooling and CNC production equipment and get a quote from the Chinese to produce the labour intensive parts instead!
Remember that it is for truly anachronistic reasons that there are still 15 manufacturers making legacy Listeroids in India. Its for the same reason that the Philipines have a back-street motor industry making parts for Wilys Jeeps.
Manufacturing came to China about 30 years after India, so China has leap-frogged the old Lister designs, and gone straight for a cheaper to build, lighter and more powerful design based on a copied Yanmar.
The only thing that drives modern manufacturing in the Far East is the ability to make the product smaller and lighter and cheaper so that you can get more of them into a shipping container.
One example is a small throw-away "suitcase" generator. The old model used to weigh 45lbs, then someone had the bright idea of building the alternator into the flywheel and ditching the alternator and governor and replacing it with a mosfet inverter to maintain frequency and sinusoidal waveform regardless of the engine speed.
The result is the generator is 2/3rd the size and weighs 28lbs. That means 1.5 time more fit into a shipping container and it uses less material in manufacturing. Yes its throw-away crap, but its what the World seems to want these days.
Rant over
Ken