No geo-IP needed. A single Price can have multiple currencies (currency_options, or "Add another currency" in the dashboard). Checkout picks the currency based on the customer's location, and you set the amount per currency yourself, so €11 can be a clean number instead of a conversion.
Alternative: Adaptive Pricing in Checkout shows local currency automatically with Stripe's conversion. Less control over nice round numbers, zero setup.
Heads up: a customer's subscription is locked to one currency once created.