Need supplier for 3 month xbox live Global or Us only

Like the title said I would be buying weekly 50-100 codes a week depends on how business goes. I am looking for global or US region ones that can last up to 1 year in storage and only dealing on GameFlip with verified sellers only.
price range from 12.99-13.99 willing to start high and slowly climb down on price so we both can see we are serious.