QF and Those First Seats - False Economy?

I have noted a few different stories about the QF decision to reduce First Class on all but 12 A380s. I note that the total cost quoted for the removal was $400 million. Lat time I checked that's about the price of a new A380. So let's just assume for a minute that we buy the PR - therefore we have a life span of 5 years for a seat. So should we consider the economic value of the decision. If you look at both aircraft then we would see that the A380 could feasibly double the number of seats from 14 to 28 (replacing first with business). For the 747s also. So we are looking at 2x A380s (net gain 28 seats). For the 747s same thing but there are 30 of them of which 4 are currently 2 class and the rest 4 class. So lets assume 20 of them will get reconfigured net gain 280 seats. (I have heard as few as 9) So the total gain is 308 seats. Hmmm I am not quite sure this is a really compelling economic decision.

So hopefully someone at QF can explain the economics of this.

Thanks

Timothy