If you get 300K with this little work experience, you'll probably earn over 1 mio in your 40s. Or do people start really high and get lower increases?
Since I started 10 years ago, I have increased my salary by around 75% and if I were more aggressive this number would be even higher. Of course, my salary is not at all comparable to yours (and also not as high) . EU and US are just too different.