What should I do about buying and selling outside the marketplace, given that the Prophet (peace be upon him) forbade it?

Selling outside the market is permissible, and there is no harm in buying from there either, because the customary place for selling and buying at the market's entrance is considered part of it by custom. Furthermore, the reason for prohibiting receiving goods before they reach the market is the fear of deceiving the seller due to his ignorance of the market price. This reason is mostly absent when selling at the market's entrance, as the seller is aware of the prices. Additionally, if the seller wishes to sell at the market's entrance and does not want to enter, buying from him is not considered a prohibited "receiving."