My $5 post got around 6 Steem + 6 SP in author rewards.

I can't explain that. Maybe it got downvoted near the end?

Steemnow in fact is giving $0.20 per Steem price

That is possible. I don't recall if steemit.com made that adjustment to the display or not. At $0.20, a $25 payout would be 125 STEEM.