Almost travelled PE to Florida last year, but was quoted about £1100 per person (high street
travel agent) for PE and found an internet return fare of £1615 per person for Upper Class....
We tend to do a cruise before going to Orlando, so fly into Miami and not Orlando itself. The tickets were bought (and have been purchased again for this Summer

) as Continental BusinessFirst tickets. Contiental does a codeshare with Virgin (so your ticket is Contiental, but your seat is in Upper Class on Virgin between LGW and MIA).
In July an economy ticket can cost about £700, so a bit over twice as much for a considerably better journey (Upper Class) seems good to me. Still, no kids yet (so might have something to do with it...)
My biggest bargain yet - although OT 'cos it was from LHR to LAX (and not Orlando) - was flying return Virgin Upper Class (on Continental tickets again) for just under £1100 per person. Its amazing what deals you can find if you look...
Flying anything other than economy can spoil you though (ask my poor husband...) and does use money which can be spent elsewhere (park tickets, food etc.etc.). Depends what is important to you (I like being spoilt occassionally...).
Boo