copy, offset, paste, then delete loop

I need serious help, not sure what to do first and I'm not sure what would be the most efficient, but the end result is: delete the duplicate ID number in column A, entire row delete, copy the number below the original ID number and move that number next to the original number in column B. (There's other data in the other columns but are of no consequence). The pattern is ID, amount, Duplicate ID. I need to keep ID and amount. Not sure if I should delete every 3 row first. Any help will be greatly appreciated. I've attached a worksheet and hope this makes sense.
thank you in advance for your assistance.

Originally Posted by Spyderwoman

... Not sure if I should delete every 3 row first ...

From row "506" to "554", the data does not retain the correct pattern.
What to do in this case ?

wow, you are good, this works great, many thanks.