Obscure definition for "amount"

Solution 1:

Selected examples from the ever-reliable OED:

†3. The full value, effect, significance, or importance of something. Obsolete.

1678 J. Flavel Divine Conduct 129 There are divers things to be distinctly pondered..before you can judge the amount and worth of it.

1726 J. Thomson Winter 9 Ye lying Vanities of Life!.. Where are you now? and what is your Amount?

1845 J. Lingard Hist. & Antiq. Anglo-Saxon Church (ed. 3) II. App. g. 397 What the real amount of that statement may be.

1881 Times 24 Dec. 5/3 The amount of it is that you have too much to say in this case.

As the definition says, this use is obsolete; I'm surprised that neither dictionary you linked marked it as such. (I've personally never encountered it--perhaps that's because I'm an American and Collins says it's more of a British thing.) Anyway, Oxford's examples are straightforward enough. If you've got institutional access to the OED, you can look at the full entry: oed.com/view/Entry/6575.