Your sums are VERY different to mine. Partly because I am closer to Spain than you.
Flights - Spain is sub £60, Florida is £550
Accommodation - room in an All Stars Resort - about twice that of a three double bedroom, two bathroom, roof terraced apartment suite in La Manga Club.
Food - about the same, but more exotic in Spain (I LOVE Paella)
Area - Parks for both places, not sure of the costs, but Spain will be cheaper as it's smaller. Not that anyone goes to the Spanish park for more than one or two days, not with the beaches cycle tracks, horseback riding etc, tennis, spa, cricket, zillions of swimming pools etc in La Manga - remember, these are in greater supply in La Manga than Orlando.
So really you're looking at spending about double to go to Orlando than Spain, maybe more. And having sampled both, I have to say they are simply different. But you get more for your £££ if you go to Spain from here. Simple as.