Premium and the Live-assisted feature are not independent products, When chosen, they become a single product, which does have a higher fee. The Live feature is an upgrade from regular Premium, and your product would then be called "Live Premium." And Live Premium would be what you would be charged for. There would be an additional preparation fee for a state return (if applicable.)
With the Live feature, you can consult a tax expert for help during preparation, and if desired, a review of your return prior to filing.
FAQ: How do I get TurboTax Live?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-product-orders/get-turbotax-live/L2kcnq0BN_US_en_US
FAQ: How to I connect with a tax expert in TurboTax Live?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/product-setup/connect-tax-expert-turbotax-live/L73wOZD5D_US_en_US