Is a guarantee whose price increases with its duration considered part of the original contract, thus being permissible, while renewing the guarantee after its expiration with an independent contract for a sum of money is considered a prohibited insurance contract due to gharar (excessive uncertainty)?

Contemporary jurists have differed regarding the ruling on a seller increasing the price of a commodity in exchange for extending the warranty period. Some have permitted it, considering the warranty to be subsidiary to the sales contract, such as Sheikh Ibn Jibreen and Dr. Sami Al-Suwailem. Others have prohibited it, such as the Kuwaiti Ministry of Awqaf, considering this increase to be in exchange for a pure warranty, which is an obligation upon the seller, and it is not permissible to take an independent price for it. As for purchasing a warranty independently, it is impermissible by consensus.