[SQL] Creating groups for a specific set of rows

I have this table

ProductID Price ID
90271 569 1
90271 455 2
90271 669 3
90271 535 4
90271 535 5
90271 535 6
90271 419 7
90271 300 8
90271 419 9
90271 419 10
90271 535 11

I need to add a GroupID column that groups the same prices under one GroupID before the next row changes the price. I can't simply use Dense_Rank() , because it creates the same GroupID for rows with ID 4,5,6,11.

Can you please advise me how to solve this?

ProductID Price ID GroupID
90271 569 1 1
90271 455 2 2
90271 669 3 3
90271 535 4 4
90271 535 5 4
90271 535 6 4
90271 419 7 5
90271 300 8 6
90271 419 9 7
90271 419 10 7
90271 535 11 8

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