While I didn’t have a Google offer, I had a Lockheed offer and that was always a company I really liked growing up (also former Marine). It was a difficult choice for me as well, but I chose Lockheed and I have zero regrets. I learned a lot about large organizations and got to work with a huge team of very smart people. Many of which who very directly mentored me. I worked there for two years + 3 years previously for internships.
When the startup bug became irresistible, I knew it was time and went and co-founded DataRank with some friends. The Lockheed experience helped me in the sense that it “validated” me, much like Google on your resume will certainly validate you.
In regards to money: When I finally went the startup root I made 1/4 my salary and had zero benefits for the first 1.5 years. If you’re passionate enough about it you won’t really care about that 1/3 salary (for a while at least). Then I bumped my salary to 1/3 my previous salary! It wasn’t until after 2 years when my salary returned to 80% my previous salary. Eventually a surpassed my previous salary, then double and tripled it, and now I optimize more for doing what I love.