Buying back an item at a lower price
Q: I am in the business of buying and selling car mags. A few months back, I sold a set of rims to someone for R1800. A couple of months later, I got a call from the same person asking if I want to buy these same rims back because he had no use for them. I made him an offer of R1200 and purchased them back. Is this considered as riba or is it permissible?