I handed in my notice today I have been with the company for 7 years and am nearly doubling my pay by going else where. Last time I got a significant promotion

I handed in my notice today I have been with the company for 7 years and am nearly doubling my pay by going else where. Last time I got a significant promotion or raise was because I got another job, stuck with the company put in the work got nothing else. Now im quitting again suddenly im the most valued member of the team and they are going to move heaven and earth to make it work. I don't like having to threaten my boss with quitting in order to get anywhere. My friend starts looking after 2 years and makes a boat load more than me. Loyalty and hard work just don't get you paid, knowing your market value does.