Never understood

It's never explicitly explained that I recall, although I'm remembering it out of context, so the context might reveal the meaning more clearly.

It could be about the problems with the park (not the ones he intentionally caused but just the regular ones they were still working on) and how Nedry has to fix them. It's quite plausible that Nedry's initial expectation for how long he'd be working at the park has already passed, but they called him back in to fix the problems that were arising. That would cause a bitter scenario between the two of them.

It's also possible that Nedry bid too low for what his services are really worth, which is why he's so bitter over the money, and Hammond just means that it was Nedry's own mistake to accept the job for that amount of money and it's his responsibility to deal with it.

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Pride is not the opposite of shame, but its source. True humility is the antidote to shame.

I don't remember much if the book explains it, but I'm sure that Nedry didn't do his job good enough or something and it sent the opening dates back a while or caused the park allot of money to fix things. He probably got into trouble for it and got punished somehow. His punishment, either a pay decrease or w/e, was his way for paying for his mistakes.

Well, John does say to Nedry, "I am sorry about your financial problems. I really am, but they are your problems."

I'm guessing Nedry probably made some bad investments or gambled his money away.

That could tie in to the whole "I don't blame people for their mistakes but i do ask that they pay for them."

Let's be bad guys.

He spent all his money on the vending machine.

Anyone here mentions Hotel California dies before the first line clears his lips.

Nedry laments the amount of work he has to do for what he 'bid' for the job followed by Hammond claiming "I am sorry about your financial problems. I really am, but they are your problems."

I took it as Nedry, out of financial desperation because of bad money management, underbid the competition to secure the job.

He tells Dodson that getting cheap was Hammond's mistake but for all we know he may well have been getting paid a fair rate but was just greedy and or desperate.

Hey! You're not old enough to drink! Now go and die for your country!!!

So I rewatched the movie and I have an idea. What if the reason Hammond says to Nerdy that people should pay for their mistakes is because Nerdy is the reason the guy in the beginning died. In that scene the raptor cage locked into place and when the gate was being raised the raptor hit the cage making it go back so he could eat the guy. So what if its Nerdy's fault that happened??? What if he didn't do soothing right and the locks didn't engage good enough?? That would then get him into trouble and get demoted.

I can see how alot of people have trouble understanding this because yes it's never explained in detail. But my guess is, Nedry is struggling financially and Hammond is with holding his income until the parks problems are fixed and this would cause alot of tension and loggerheading between the two of them. This would also explain why he's working with Dodgson to secure embryo's for his company as this will earn Nedry a tax free one and a half million dollars. Nedry sees Dodgsons offer as an easy way out of a difficult situation and also a way of being able to give Hammond the middle finger.

It's not made clear in the movie. I think in the film it's meant to be a commentary on Hammond not paying for his mistakes.
In the book, however, Nedry is angry because he is forced to come back and change the computer system because Hammond changed what he wanted. In Nedry's opinion, he did his job, and Hammond was unreasonable in expecting him to come back to make changes at a later date, because they weren't "mistakes" they were changes