They aren’t though. $5M is the cost of a single training run. $500B includes the cost of operations, data center, a lot more failed runs because they weren’t sure that they’d were on the right path etc.
It was orders of magnitude more before DeepSeek.
[0] https://newsletter.languagemodels.co/p/the-illustrated-deeps...
Well yes, yes you did, because all you had to do was follow the existing instructions, guidelines, and use easily available materials. You didn't go down any dead ends, didn't have to work your way from propellants like high test peroxide, dangerous hypergolics, and eventually develop solid rocket boosters.
It's like making the generic of a drug someone else developed.
Even if you merely flipped a single bit and created AGI based on existing tech, you're still the legitimate creator of AGI.