Square Enix are releasing a series of four compilation LPs with character and battle themes from all 15 Final Fantasy main series titles.

Each release will be a single black vinyl LP. They will be housed in tip-on single-pocket jackets with character illustrations by Tetsuya Nomura and will all include a download card.
There is also an option for a version which has all four releases together in a clear plastic slipcase

Please note that if you order from Square Enix Japan you will have to buy all four standalone titles in order to qualify for the slipcase, while the Western stores has the 4LP set as a standalone listing.

They are priced at €33/$37/¥3250 and are scheduled to release between December 6, 2021 and March 28, 2022 (slipcase orders will ship March 28, 2022).
It can be preordered via Square Enix Europe here, Square Enix North America here and Square Enix Japan here.