Originally Posted by
CargoOne
Your statement is simply not true. There was 5150 x 737-800 produced vs 5750 x A320 (just 320 excluding 319/321). If -800 would have a better economics it will for sure sell in a much larger numbers compared to A320. In reality both types have advantages and disadvantages against each other but all in all they are just about the same the cost wise. For example you are correct regarding better payload/range of -800 but then just as a wild guess only 0.1% of -800 departures are calling for the range/payload which A320 cannot do.
To add to this: apart from the numbers game which might slightly favor the -800, the A320 appears to be more popular with pax (and pilots, but that doesn't matter for business).