Okay so your S4 beats out the 335i sedan in your 45k-55k, except the S4 starts at $47,300 and the BMW 335i sedan is at $42,400, that's a $5000 difference, and puts the 2 cars in different "class/price ranges" according to your listings...
The 335i X-Drive M-Sport would be the S4 competitor from BMW and the closest thing to that in the F30 iteration FOR NOW would be a 335i Sport-Line X-Drive which would list from $46,995. Just $305 LESS than the entry price for an S4 (which has more std. equipment too...)
Of course a base level $42,xxx 335i would not have any of the sporting upgrades the $47,300 S4 does even in base form... The 3-er doesn't even have leather heated seats at any level standard so it lacks many of the luxury upgrades too.
And the $45k-$55k pricing (or any of the other ranges) wasn't in reference to base prices but actual purchase prices for equipment that I would want. Cars I would BUY in 'X' price range. Not cars that are merely priced FROM 'X' price range.
The S4 I had in mind with the $45k-$55k car choice is a Premium Plus S-Tronic w/ Sports Diff, B&O Sound, and 19's for $52,325.
A comparable 335i Sport-Line X-Drive with 19's, Cold Weather Pack, Premium Pack, Premium Sound Pack, and Sport Auto would cost $52,595.
SEE... And at these prices the S4 is the clear choice for me for a $45k-$55k (the range in which both cars THAT I WOULD BUY fit) price range.
I have done this pricing for ALL the cars I listed for my choices (and their competitors of course to allow the choice to be made)...