Traveling with a baby

Hi mommas!

FTM here!

We are going be traveling with our son in a couple months across the country. The flights / travel times are almost 9 hours long… we didn’t buy another ticket to bring his car seat in with us, we were just going to hold him the whole time. Does anyone have any advise / experience with traveling with a 4 month old?

Should we suck it up and spend another $400 for a ticket to bring his car seat? Or does anyone have any products they recommend when traveling to make holding the baby the whole time easier?

Or products that help with traveling with a baby easier in general??

Thank you!!!