Take the US Pinsider prices with a grain of salt. Canadian pin prices are typically higher than US (supply/demand).
You're more likely to sell to someone on PREV or MAACA, even if they're from London/GTA. We are right on the border but my experience is that US customers don't want to cross the river even though there is no duty/taxes on their purchase. Kinda strange, considering the exchange rate.
Hope everything turns out ok for you. Maybe you can start with selling the pins that are easiest to replace (ie. LOTR..VE) - that might make it easier to make that tough decision.