Probably only talking £100's of a price difference, unless you have a 2jz laying around like some people
custom mounts, fueling, new ecu, upgraded parts on the 2jz for big power, adapter plates, custom rad hoses, custom exhaust, gauges,
lot easier to stick some forged rods and a turbo on the vq.
But if its an engine you are more accustom too then you can use your knowledge to save money.
I would be half tempted to stick a vq in something if I had a spare car and engine.