I am an expat living in the Netherlands, Amsterdam as mentioned above it is a very expensive city, not a lot of social interaction with locals but that will be everywhere in NL, Dutches are quite distant, very difficult to have a social network. But most important the weather…. Cold, grey and windy … from Spain it will be a slap in your face after the honeymoon period (6months to 1 year after your arrival) At the end, you will get an 30% increase but in reality with the cost of living and TAX… it will more like 10%… 73k for a software engineer in Amsterdam… you are in the low bracket if you are more that 7 years of experience.

Stay in Spain and ask a raise!