So...I'm in the same boat with you guys, didn't play differently with 2 temples, 2 nests, and 1 den. And about 500 points away from the last prize with 1 day 4 hours left. Hmm...
I did a search and yes, the last dragon needs more points compare to the previous world event (Halloween, Skeleton dragon), about 450 more points, but about 1000 less points compare to previous previous world event (Masquerade dragon). With the Skeleton dragon, I was able to reach it just barely without spending gold. As for the Masquerade dragon, I do remember needing to spend some gold (I think around 150 or less) just to achieve it.
So basically I'm at the same progress as the previous World event (Halloween), but did worse compare to previous previous event (Masquerade). Hmm...I do like the last dragon, black blue wolf (pretty cool) and that it'll help with coming up Dragon Tales (which I'm not sure if I'll even participate depending on prize and requirements); but also keeping in mind Black Friday is coming up with many rumors about Gold Producing dragons (not even sure if that's even true...). So I highly likely need to save my gold and forego the Frostwolf and just attempt to do my best on DT if I choose to do so. Sux, but what can I do?...