What is a word for overconsumption with the goal of getting your money's worth?

Solution 1:

milk / overmilk

milk (v.)

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To draw or coerce profit or advantage from illicitly or to an extreme degree: EXPLOIT

milk the joke for all it's worth m-w

overmilk (v.)

to exploit (something) to an excessive degree

The overall … fall in 2010 could be attributed to greedy promoters overmilking the market. m-w

(Translation: You are at Disneyland with a Park Hopper ticket, but it's up to you how many rides you go on before the park closes....The price of your ticket has been paid in full, so I say you milk it for all it's worth!) Levi Lusko; Swipe Right (2017)

MR. O'NEILL: And they lost $37 million RFC money, and the house was priced at $16,000 when they went under. MR.BICKET: And the members of the corporation milked it until it wasn't there any more. US National Commission on Urban Problems (1968)

Armstrong doesn't overmilk it. He's quietly effective as Davis would acknowledge: “I'm there to give it my all, because I'm the star, and then they show a closeup of Louis and suddenly it turns into a Louis Armstrong movie. Kevin Whitehead; Play it the Way You Feel (2020)

There's no doubting this musician's technical arsenal—breathtaking passagework, silky diminuendos—but this was an overwrought performance with every legato overmilked and every plangent phrase drenched in anguish. Times, Sunday Times (2008) Collins

"What I hope doesn't happen is that there is a flood of incompetent product," Atlantic's Azzoli says. "We have a tendency to kill or overmilk good ideas in this business." Billboard, June 14, 2003

Solution 2:

Though not a single word as requested, you could try the common phrase:

Squeezing [all] the <fun/enjoyment/etc.> out of

to get or obtain something from someone with difficulty, or to cause something to happen by a continuous and difficult effort

Cambridge Dictionary

This implies that there is still something to be obtained from the task, but it comes at great effort, and that the source will be left barren. It does not quite convey that the person continues once there is nothing left, but this could be made clear by combining with additional wording:

Stubbornly ...