Depends on if you want a retirement at a reasonable age or if your rich enough to support yourself and fly.
Many will tell you go for it if thats what you want, throw caution to the wind.......However they dont mention that when you get into your 50s, 60s etc, how much fun it is to work 14 hour work days and still have little retirement or benefits. Yes there are good jobs that will reward you financially, but most who work in this field are somewhat Nomadic and go from job to job at a variety of times.
30s is not old to start, but the limiting factor may be how long will it take you to build time for a hirable resume. Lots of folks out there with 4000+ hours looking for work...Companies know that and treat you accordingly.
On the other side of the coin, Im just past 60 with a retirement coming in from another life. I have no problem finding part time work. Employers like that as they dont have to pay benefits and I like it as I dont take work away from someone who needs it to live. I just fill in when someone needs a break.
One of my part time jobs just went to a guy who has seperate finances. He is working for FREE to build time, the company loves that. That really hurts the industry.