You will see the item as something along the lines of: KORG TRITON EXTREME 88 BRAND NEW.

Then there will be a ridiculously low start price usually £1.00, but if you read the description it says Email me for a Buy it now price of 900 euro's.  Do not be taken in by this as you will then find that the seller will accept payment through Western Union, another deifinte no no and he will ask you to declare the money as a gift to a friend, his excuse is so that he doesn't have to pay tax on the funds, but you will pick up the tab for these tax funds instead.  You will be told that the keyboard will be sent via courier and that it will be 48 hour delivery, enough time for him to collect your money.  You will find that 900 euro's equates to about £650.00.  This keyboard sells for anything from £1700.00-£2200.00 when brand new.  If you see it cheap like this and with an email address offering buy it now, then be very cautious and only trade if the seller offers Paypal and if your gut tells you it's genuine.  I knew it was a scam, as soon as he contacted me and told me Western Union and as soon as I was contacted back, the item was taken off e-bay.  I did not continue with this trade, but pretended to go along with it.  The next day the same item was on again, the same e-mail address, but a different seller name.  Sadly I didn't get either name, but I am sure that wouldn't matter as he changes it every time and the country of origin is always different with each name too.