Usually, this means an operational component where you can improve on efficiencies and save on costs, or a sales and marketing component where you can directly drive revenue.
The ability to straddle multiple disciplines and communicate effectively in each is valuable.
The other option is to start your own business, i.e. services, consulting, etc. $300K isn't that much in terms of annual net income. This is still doing what I mentioned above.
Speak at conferences, publish a whitepaper, write a book... depending on your personality, merely having a public presence can be enough.
It's entirely possible to do something you love for a fun team with good technology and a product that genuinely benefits the world as a whole, while earning a better than market rate salary.
Try not to mistake looking out for your own interests with disregarding everything apart from money. They're orthogonal.
After considerable reflection and a decade in the marketplace, I have come to the conclusion that there are two kinds of people - those who appreciate the value of money and those who do not- and it cuts across cultures.
The former are most times sheep (sometimes not) and employers are grateful for their existence. These are the people only too happy to do valuable work for a company whose goal is profit in return for a pat on the shoulder and maybe, if they are lucky, a gold watch after 25 years. Is this attitude derived from an indoctrination process or is it innate? I do not pretend to know the answer. What I do know is that in a capitalist system- which the whole world practically is- employers depend on a significant population of the workforce to act with timidity. Many businesses are built and fortunes are made on this assumption: that the help will be paid less than he is worth and he can be counted on to not complain. Capitalists will ruthlessly cull the herd to maintain the s.q.
It is not out of place to ask for more money if your skills are up to par and the company can afford it. Money buys comforts, it soothes the pains and sacrifices one makes to attain present position. Enough money permits me to endow chair at a university or build a school/clinic in rural Africa or Asia. I may decide to contribute the excess to my preferred charity that provides open heart surgery treatments to newborn with congenital heart defects. It opens up the option for me to run for elective office and effect change where better men can only complain. Most importantly it reflects my contribution to the system and serves to tally the score.
OP's desire, for money and the desire of others - is not greed. Its a personal choice. It is pragmatism but as I said before not everyone sees it the same way.