I spent all 600. The reel is so annoying, all of those five stars but it’s just gold. Also I’ve had some pretty crappy rollovers.
I have Goldpool and duped him from the original event. He is actually a decent champ, but really not worth overspending to try. I would suggest buying as many crystals as you would be comfortable being a big boost to your gold stash, and try those. If you get him, great. If not, you aren't missing out on that much of a game changer, especially compared to other champs who have come out since.