In theory you SHOULD get Double MQM only on the base and the 50% bump.

i.e. for 1000 mile flight, you would get 2500 MQM (1000 x 2 + 500)


What I have found with these DL promos (even though the terms say otherwise) is that you end up getting Double MQM on the total

i.e. for a 1000 mile flight you would get 3000 MQM ((1000 + 500) x 2)