Not for the same audience but for much the same idea I made a progressive visualization of saving and compound interest in a blog post about pension saving:
Surprisingly the GP didn't include price of the device as a reason, but the 30% Apple cut/likely uplift in price that developers need to charge to recuperate development costs - which are far more significant than developer hardware costs.
A non-Apple device without the moat would be better. GP also didn't ask for free apps.
https://calcwithdec.dev/posts/pictures-pensions/
I intentionally didn't include numbers at all - they are a bit more effort to interpret.
A visualization might be a nice feature for kids (but it probably depends on the kid!)