Hello dear hiring manager, this is Deepan a professional Web Manager and I can simply edit prices and add variants to your 300 existing products with 100% accuracy and quality to your Shopify site within 1 day of project acceptance. I am trying to build up my portfolio on freelancer, so I will provide you 100% accurate service within 1 day of project acceptance and do not acquire to release milestone unit the project is 70% done upon accuracy and quality. Please, don't hesitate to contact me with any details or updates you may have and I am looking forward on working with you. Thanks, Deepan!