It is permissible to charge more for purchases by installment than when a person is paying in full at the time of purchase. It is also permissible to name one price for cash sales, and another for payment by installments made within certain periods.

The more correct opinion is that Sujud al-Tilawah is an act of worship, but it is not like prayer. So, it is not essential to be in a state of wudu or to face the qiblah when you offer sujud al-tilawah.