There's always risk that what established players do is not going to work well for the newcomers.
$5 in flags will not hurt a huge contest maker, but can cripple a small account for months.
I cannot reinvent your content for you.
I can however suggest that you find a way to scratch anything about Up-vote being required to participate.
I previously ran a lottery for little game community and I just required a very specific comment to participate.
Sure, the rewards do suffer when people can skip the up-vote, and your own growth may slow down.
I encourage you to think of some regular content to boost your numbers.
Also, participate in other people's contest.
@majes.tytyty basically gives $0.15 up-votes for very little effort on an almost daily basis to all valid entries in their Vocab-ability posts.
Basically, try to diversify.
RE: Payouts "Find the Missing Number" Daily Contest for 2 October