Google actually hires a large number of junior-to-midrange engineers and trains them up. Average age at Google is something like 28; a large number of Google engineers have never worked anywhere but Google.
At that level, they hire for aptitude, not experience. The $60-80K that Google pays for beginning hires is on the anticipation that after training, they'll be worth at least that much, and Google can retain them long enough for them to make it back. It's fairly common knowledge that a new Google engineer won't be productive for 6-8 months at least.
The risk that a startup runs by paying $35-45K is that they'll get people with lower aptitude who'll never turn into experienced engineers. That's a pretty big financial risk to take, particularly for a startup with much less runway than Google.
At that level, they hire for aptitude, not experience. The $60-80K that Google pays for beginning hires is on the anticipation that after training, they'll be worth at least that much, and Google can retain them long enough for them to make it back. It's fairly common knowledge that a new Google engineer won't be productive for 6-8 months at least.
The risk that a startup runs by paying $35-45K is that they'll get people with lower aptitude who'll never turn into experienced engineers. That's a pretty big financial risk to take, particularly for a startup with much less runway than Google.