There are product names that are similar--so be careful what you ask about. "Premium" is the name of an online version of the software, and is only web-based. Premium is not available anywhere except from TurboTax. Premium is available as "do-it-yourself" online software, or in "Live Assisted" or "Full Service Live" for various amounts, with separate fees for federal and state returns.
"Premier" is the name of a desktop download version, which can be purchased from TurboTax for $115, or from a variety of retailers. You need a full PC or Mac to use Premier.
DOWNLOAD (This requires a full PC or Mac—-cannot be used on a mobile device)
https://turbotax.intuit.com/personal-taxes/cd-download/
You can also purchase the desktop download from various retailers such as Costco, Amazon, Walmart, Best Buy, Staples, Sam’s Club, etc. etc. etc.
This link Where can I obtain authentic TurboTax software? has a list of authorized TurboTax resellers.
When you use desktop software, there is an additional fee to e-file a state return. You can avoid that fee if you print, sign and mail the state return.