We're a small web design/development company based in the north of England we typically charge 65 per hour plus VAT for development work e.g. coding etc and 50 per hour plus VAT for SEO work.

If you live and work in Holland then yes you'll have to pay Dutch taxes.

I worked for a year in Spain and had to register under their social security and tax system to be properly legal. Of course there's always off the books work which has its pros and cons...