What is the ruling on building tombs in the form of multi-story structures and buildings, writing on them, and burying people in them collectively for a fee, and is a will for a Sharia-compliant burial permissible?

The deceased's will to be buried according to the Sunnah is obligatory if it is known that their family will deviate from it, and it is recommendable if it is known that they will not do so, especially concerning matters related to burial. Scholars have differed on the ruling of renting land for burial, and the most likely opinion is that it is not permissible, because it is not allowed to exhume a grave before the deceased has decayed, and the time of decay is unknown.