Although the new Omnath is one of the best-looking commanders in Zendikar Rising, it will rarely see play in any other format.
Niv to Light players may find its extra utilities very useful, but other than that exception, Omnath will tread water for now.
The last Omnath printing from Core Set 2020 faced a similar situation. It started off as a $20 card, before dropping to about $5.
Omnath, Locus of Creation is a bit better than its M20 alternate, so it may still fetch around $10, but don't expect it to push that envelope very much.