I live in Dallas Texas, and my local Costco did not have this battery in stock, so I ordered it online from them. I received it within two days of order (30 pounds, free shipping) Please note that this is a slightly longer battery (Group size 46B vs original group size 34B) so you have to use a small sledge hammer and bend the metal bracket that holds the side of the battery in place. Reference attached photos. The original battery only has 35 Ampere-hours (Ah) and 272 CCA (Cold Cranking Amps). The Costco battery has 41 Ampere-hours (Ah) and 410 CCA (Cold Cranking Amps). https://costco.interstatebatteries.com/ Here's the Costco URL. Search on the regular Prius model (not Prius C).
My 11 year old OEM 12v battery decided to start going bad this past Friday. I was able to get an exact match S34B20R group size from local advanced auto parts store. It is 340 CCA and 425 CA (which relates more to Prius C as their is not starter and CCA is not needed). Took me 5 minutes to remove and 10 minutes to put new one back in along with seat skirt and put the tools up (10mm socket/rachet and flat head screwdriver). I dont have a costco membership (nearest costco is 2.5 hour drive).