What job specs are these?
Don't forget cabin crew earn allowances and flight pay. Ground staff at some airlines may earn shift pay. Factor in you have to drive in every day and bring or buy lunch, you can end up being much worse off than flying staff.
Of course, this all depends on the airline in question. Working on the ground can be very stressful. I've done both and they each have their pros and cons but I can say that personally, on the ground, I didn't earn anywhere near as much as I should have considering what I had to put up with.