Inky/Pugwash
You'll start at college on the square root of sod all, maybe £900pm take home, thats including the accom payment. College lasts between 4 months (Aero) and 11 months (Area). Add in another 4 months for a failed course and possibly 3 more for a business hold, and if you are unlucky you could be there 2 years.
On leaving college, dependant on where you are posted, you'll get between £15-18k p.a. (+ maybe london weighting). Believe theres still a one off payment when you leave college of £1000 for relocation.
Again, unit dependant, validation takes between 6 months up to (i guess) 3 years? Area usually takes longer than Aero during Live training. Upon Validation, unit dependant, you move to the Valid Trainee point, which is between £34-39k (inclusive of shift pay)
Then on third anniversary of starting college, assuming you are valid, you move to the main ATCO scale, and progress a point up this scale per year till you get to the top. Add in extra point for OJTI duties, 12-15 years to the top of the tree, which is between 65-90+k.
There is also flat rate overtime per shift available at some units.