depending on the year of the car etc, it's better to buy a 1/2 cut, then it is litrally a matter of pulling everything apart, and just bolting it all back in.
minimum it will cost you is $2500, not including the labour. but remember - you get what you pay for.
last year i bought a motor/box out of an aussie car when a guy was doing a conversion. he bought a cheap rearcut interstate, sight unseen. turns out that the wreck had been rolled - and the motor required a rebuild (not known until motor was fitted and started). warrenty claim? - your problem!!. their suggestion was to put the motor back into the cut and ship it back, and they would refund his money (as they did not have any other ones)
basically what i'm saying that the cheapest advertised price is not necessarily the best one to buy....