I delegated 5,000 SP to @steemmonsters and in return, I received 1,100 +/- 50 DEC per day.
So, 600 DEC used to promote a contest post is more than 1/2 of what I earned from the SP delegation.

I also promote posts based on merit at 120 DEC and above.

I am sponsoring 6 contests now at 2 STEEM + each - plus if there were more than 6 entries.

Trying to keep up with a growing community.

At some point, contests need to be more self-sufficient as contest posts earn more per post each week.