Costco does appear to offer Nespresso-compatible pods — but with a twist. They are (technically) not Nespresso brand pods, but rather Starbucks by Nespresso pods.
Costco lists the pods on their website, which include a variety pack with a mix of Starbucks Blonde Roast, Dark Roast, Pike Place Roast, Colombia Roast, and Espresso Roast.