I need help

So I bought a domain last year November during m//i//m//a//s//t//u//d//i//o. King

Listed it for sale in top marketplace with dan.com as it's main lander. I realised after a while the domain starts getting views and clicks for the Netherlands.

July this year I got an offer $2500(initial offer) for the domain from a guy in Netherlands (dan.com says he company's name is an exact match to my domain). Truth be told I didn't know the value of that name infact I've tried outbound to sell for…