Please be aware of scams that have become widespread in targeting sellers advertising equipment, automobiles, and other items. Often this involves buyers from Nigeria, Africa, Netherlands and even other locations overseas.
Usually these offenders send email offers to purchase your equipment or other items at a price much higher than you had asked, then mail you a worthless Money Order or Cashier's Check for an even larger amount and ask you to refund part of the overpayment to another person they owe money to for some other transaction or service.
Keep in mind that not all emails you receive will be scams. However, when someone wants to "overpay" you, and you have to send them cash, then this is the sign of a scam.
The Money Order or Cashiers Check may appear to be legitimate and your bank may initially accept it, but be warned that it will likely be returned as a fake.
Please be warned, that this type of scam is widespread, and these people are ruthless and manipulative. You can find more details at Webfarmer Equipment Scams http://www.webfarmer.com/scam-alert/index.htm
Don't be fooled. If it sounds too good to be true, it probably is.