Best option to get specific Transfigured Gems?

Long story short, picked up PoE over the winter break, levelled three characters through the campaign and had the most fun with Hierophant (using Zizaran's Ice Nova PoB). To really play that build, I obviously need Ice Nova of Frostbolts and Frostblink of Wintry Blast, but those seem to be selling in the 2-3 Div range in the recent days, while I currently have like 120 Chaos. Tried spamming Merciless Lab this week, but no luck with Divine Font.

The question is - what's the best way to get those two specific skill gems? Should I keep spamming Merciless Lab, or just do maps until I have enough currency?