Cheeper -
Tukwila Interurban, B20 from Pacific Pride. Same old great price. Near the Harley dealership/Penske/drive thru Starbucks off of I5. North of Southcenter, south of Boeing field exit. Pettit has a deal with getting the same card. Much more civilized here in Tukwila than stinky Seattle
Oh, Safeways in West Seattle should you ever be up there also has B20 for an acceptable price.