How to Hunt Trapvine
Repel Fog ritual cost depends on the distance the fog is currently at. If you let it come closer it’ll need easier materials again. If you’re seeing trapvines you’re already pushing it very close to the max distance if not there already so doing another ritual won’t help much.
What you can do is build some Fog Aegis near the fog to stop it from advancing and give enough time to the trapvines to mature. Alternatively if you wait a few days there’s an upcoming update that will make them significantly easier to get(it’s already live in the beta branch).
Using aegis help, but the only thing you need is a mage with high nature skill or more if you can. Harvest it with maximum priority. That’s it. Don’t expect to catch many of them, but at least enough to start farming.