|Answer: Brief parameters of Lo sachmod - You shall not covet.|
One who desires another person's belongings and makes plans to obtain them, transgresses the commandment of Lo Sisaveh (Devorim 5:18). If one merely desires something but makes no plans to obtain it, the Shulchan Aruch rules that one does not violate this prohibition. If the person takes action and pressures the owner to give him or sell to him the item, and succeeds, then he has transgressed Lo Sachmod (shemos 20:14).
If one desires an item it is permitted to approach the owner to ask him if he would like to sell it. The prohibition applies only when one pesters him and pressures him until he agrees to sell it or give it. Persuading him via others, such as getting a friend, associate or influential person to persuade him to give it away or sell it is also forbidden.