27 is not too old. Plenty of guys starting out who are older than you.
Go to your local airport and check out every flight school and compare. You can probably get everything done for $50-70K. If you drop everything and dedicate 100% to become a professional pilot, you can get your ratings between 7-10 months. If you work full time and dedicate your free time to flying, you could be done in a year and a half maybe.
Flight instructor jobs are plenty if you are willing to move to the right place. A year and a half of instructing and you’ll have enough hours to go to the regional airline or your choice. Currently, guys from my airline are getting hired at places like Frontier with just over a year at my company, less than two years to Spirit, less than three years to Jetblue, and we even have had guys with less than three years get hired at Delta but that’s atypical.
There is a lot of hiring and movement right now and the retirements at the majors hasn’t even hit peak yet.