Is it permissible to continue lending money to someone in exchange for him providing me with goods at cost price, on condition that I benefit from selling these goods and he benefits from the money lent, then he repays the lent amount to me without any increase or decrease?

Selling some goods to the borrower at the price at which they were purchased is invalid and forbidden, because it falls under "a loan that brings benefit," which is usury (riba). Any benefit stipulated in the loan is considered a forbidden increase. The Malikis, Shafi'is, and Hanbalis have explicitly stated its impermissibility. Ibn al-Qayyim forbade combining a loan with a sale due to the potential for it to be a means to profit from the loan.