Can I pay for Turbotax 2019 Online version now? I only see "Pay only when you file" available but it looks like there is a time-sensitive promotional price available now.

Yes you can pay early to lock in a lower price.

you can say you want to print and it will make you pay first.

1. If you're not already in your return, sign in at TurboTax.comand then select Take me to my return.
2. Select Tax Tools and then Print Center from the left-side menu (on mobile devices, tap in the upper left corner to expand the menu).
3. Select the first option, Print, save, or preview this year's return and follow any additional onscreen instructions.