IMAC 21.5 2.7QC 2X4GB 1TB (8J2) NOT TURNING ON

THIS UNIT DOES NOT POWER UP.HAVE BEEN TOLD THAT SYSTEM REQUIRES A NEW LOGIC BOARD AT A COST OF 5000????

                                                          THIS ITEM BEING SOLD AS IS (A NON WORKING ITEM)

                                                                2 and half years old bought for 21000-00 rand new