Is the ruling on delaying the receipt of money from selling goods for a period of 60 days, with the possibility of the website or bank using the money in usurious transactions during this period, considered aiding in sin?

There is no harm in selling permissible goods through the website, and the website reserving the price does not affect the permissibility of the transaction. The possibility of the bank using the amount in an unlawful transaction without permission does not affect it, and you will not be sinful due to unintentional or indirect assistance in what is unlawful.