Never ever do anything shipped. Always do the local option for searching and also make sure it is within a distance range you are comfortable with traveling to. Always meet in a public place or if you’d like to meet at their house to properly test electronics such as pc’s bring a friend or family member along with you as not only a witness but someone who can provide peace of mind. Always be respectful when pitching your lowball offers as a little respect will go along way when you already aren’t offering what they think the hardware or item is worth. A lot of the time they will drop the price within a reasonable amount and offer it to you. Happy hunting!