Looking for a word that means 'far more than necessary. Like if I needed 5 apples, but got 25, my gain or success would be described as...X. I think I may have heard 'overt' used like this in the past, but not sure. Not exactly like 'major increase', and basically the opposite of 'marginal'. Thank you guys!
The word I immediately thought of, which sounds similar to overt, is overkill:
2 : an excess of something (such as a quantity or an action) beyond what is required or suitable for a particular purpose
// publicity overkill
// an overkill in weaponry
In describing the situation in the question, you might way the following:
Buying 25 apples for a pie is overkill.
It has a more literal sense, but is often used in this figurative sense too.
2. Of qualities, states, actions, magnitudes, etc.
b. Exceeding what is right, proportionate, or desirable; immoderate, inordinate, extravagant.
1875 B. Jowett in tr. Plato Dialogues (ed. 2) III. 681 A single night of excessive rain..left the rock of the Acropolis bare.
excessive (adjective): exceeding what is usual, proper, necessary, or normal
1 (adjective) in the sense of immoderate: The length of the prison sentence was excessive considering the nature of the crime.