Premium is about $5/gal CDN. $1.30/L x 0.75 conversion x 3.8L = $3.705/gal US for 91 octane. 94 is way more expensive.
Is your premium 91 octane? Because premium here is 93 Octane. We get 87, 91, and 93. Some stations have 89, but it's not all that common. The 93 runs about $3.35 US a gallon.