I think the majority of the cost is when you stray from the stock L28ET to aftermarket. The initial cost is finding a donor car. 200-750. The rest is labor in the swap. For real performance your range is .01 - $$$$
If it were me in your situation, don't do the swap. Finish school, get a good education, drive the stock 240 the way it is. Once your done, have a good job, buy a house and go crazy on the car.
Oh and don't get married just yet. Finish the car first, then get married!