Of course you can. You get the same motor in the S that you do in the Autobahn.
I got my S for $24K. The R was $38K minimum. Haldex AWD + 60hp + an extra 300lbs isn't even remotely worth $14K.
It's not just about the engine. SE-Autobahn, there are differences in trim above the S, which is why you really have to compare R to Autobahn. LED, pp, cc seats, etc.
No one cares if
you don't care about the options available above the S, they are still there in the R and they still cost actual physical money. They are part of the car. There is nothing you can do about it. The math doesn't care about that, either.
That's why thinking "it doesn't matter" when comparing the cost of those models is silly. You're conveniently annoying actual real things that really do cost money, and so by comparing Autobahn to R you are essentially eliminating the bulk of those costs in the price differences as a fairer evaluation of the cost difference in performance from R to GTI.
You're right that Haldex + 60hp isn't worth $14k; because there's a lot more in that $14k that the S doesn't have, and it's real cost that you can't ignore.