Indicative only, depends on location, k's, condition, model origin etc - In Sydney expect up to $1500 for an engine, loom and ECU; $2000 with an autobox and around $3500 with an R154 5 Speed/ECU combo.
Check your sump requirements too as there are 3 possible combos (front, centre and rear) to clear the destination crossmember and steering rack.
Get some sort of guarantee on the turbos too - a lot with blown rear turbo comp wheel can be found.
You can occasionaly find the odd un-needed engine privately for under a grand.
Good luck