There's no difference in development or production costs,
you really do not understand economy of scale when it comes to integrated circuits.
you are making 4 scopes :
1 - 4 channel 200 mhz 1 million points 4gs/s
2 - 4 channel 200mhz 4 million points 4gs/s
3 - 4 channel 500mhz 1 million points 4gs/s
4 - 4 channel 500mhz 4 million points 4gs/s
50% of the buyers go fo rmodel 1
25% go for model 2
20% go for model 3
5% go for model 4.
you assume there will be a total of 1 million scopes sold.
half a million model 1, quarter million model 2 etc ..
if you need to write off the development cost of model 4 over the volume you will sell these will be very expensive machines.
The maskset for a typical scope asic is around 4 million $ ... these days. so you are burning 12 million $ to cover 50% of your targeted volume ! ( models 2,3 and 4 combined are 50% )
and you need to make 4 boards, etc ..
now, if you make the thing programmable. you pay for 1 maskset that covers 100% of the scopes.
The cost of the chip itself ( the cost of producing the silicon , assuming everything else is already paid for ) is purely dictated by square millimeter. having a chip with 1 megapoints go to 4 megapoints adds maybe a square millimeter ... which will cost you 1 $ ...
but, throw in the development and mask cost ( if you are only going to sell 50000 of those machines and that all of a sudden becomes a much more expensive chip !. )
if you make 1 million chips . the chip itslef costs you 5$ in silicon and 8$ in mask cost and add in 20$ development cost (10 million dollar to design it spread over half a million chips) . let's say 30$ total
for the chip for the hi end machine : it will stilll cost 7$ ( slightly larger area ), but now you tack on the 10 million dollar split over 50000 chips... which is is 200$ and the mask cost split over 50000 chips... which is 80$ ..
and the chip will cost roughly 300$ ... . add all that stuff up for your 4 designs and thats a lot of money !
do everything with 1 chip. 7$ in silicon (we're always using largest die ) , 4$ in mask ( 4 million spread over 1 million chips now ) and 10$ devcost ( 10 million spread over 1 million ) and that chip costs you 21$ ..
you can't beat that price. The most profitable solution is to mass produce the high end chip and simply disable functions. the cost of the silicon is nothing compared to the design and the startup cost !
that is the reality of semiconductor production.