It's unclear who a prospective purchaser might be, but it's safe to assume that whoever buys it doesn't plan to restore it to airworthy condition (I suspect it might actually be engineless).
So the condition of the paintwork and, up to a point, any surface corrosion probably isn't going to make much difference to the price achieved. As alluded to earlier, preserved NF.14s are ten-a-penny in the UK, which might explain why it's taken the RAF so long to get around to disposing of it.
ATC units with their own airframes are becoming increasingly rare - a few years ago, I used to take my grandson to a soft play located next door to Tolworth ATC Squadron in SW London, who had their own Harrier (must have pulled a few strings!). But it has now gone, sold to a collection in the USA.