Is it permissible to purchase a house through a usurious bank using a Murabaha system, whereby the bank first owns the house and then sells it to me for a fixed, deferred price, knowing that Islamic banks raise the price significantly, and I am a single young man seeking to marry and start a family?

If the bank genuinely owns the property before selling it, and does not impose usurious interest on delayed installments, then there is no harm in dealing with it. However, if the transaction involves usurious interest upon late payment, or if the bank stipulates that the ownership of the property will not transfer to the client until all installments are paid, then it is not permissible to deal with it. This is because it contradicts the essence of a sales contract, even though it is permissible to stipulate a mortgage on the sold item to guarantee the installments.