This bug occurs on the standard audio upload widget on the develop page.
If you upload a valid audio file and focus the textbox to change the audio name, pressing enter with the box in focus will entirely skip the “Estimate Audio Price” step and upload the audio without showing the estimated price at all. It still uploads at the required price, but in the event of a longer audio file I could be using R$350 without knowing it.
Just thought I’d bring this up. Just found it out.