Most software devs start at 2.5k in NL unless you're severely lowballing yourself. You're lucky to get 6k before becoming a principal SE or architect. 10k is a salary you're more likely to hit self-employed.

4x is possible, but in that short of a timeframe, you're more likely moving from a Dutch company to an international one and becoming employable across the entire globe. Which given US salaries would give the ability to 5-10x anyway.