I think this largely comes from being a protagonist in a DnD campaign for a long time, especially a roleplay heavy one. DnD characters naturally build a portfolio of exploits that any NPC character would think insane to accomplish.
If you want the true gigachad energy though, the spell she used to contact Talona was Divination, which requires a sacrifice to the deity in question, worth at least 25gp.
Konsi thinks it's good etiquette to make your sacrifice something the deity would approve of. For example, when she contacted Selune, she crafted some art-piece quality functional navigational tools out of silver and used those as the component in the spell.
As Talona is the goddess of poison and decay, Konsi decided that a suitable "sacrifice" would be a bottle of lethal, slow acting poison. She spent a few days gathering appropriate herbs and mushrooms, made the poison, then promptly drank it to sacrifice it.