Nah, don’t spend money for this.
Try to solve it with the rewards from the daily rankings. Reach the 1.2k Quest at the end of day and be at least #25, you’ll get 1k. And the 2k Quest with ranking min. at #15 is also doable..
Or you can keep 4/5 fights vs. the epic monster, will give you ~900 coins for the 1.2k Quest. And the 4/5 fights vs. the legendary one are ~1.5k for the 2k Quest, I think.
One of those strategies will do it for me, to usually hop over these hurdles..