I have got to agree with the others. The cost of the swap has got to be greater than the savings. One exception would be if the parts were already in your garage.
Another might be if the automatic transmission was already bad.
If the price is that good, buy it. Drive it for a while. Look for a manual. When found, trade it or sell it.
Once the car is converted, the resale value of the car is greatly diminished. Consider there are many ppl out there that would not even consider a car with that much "surgery" done to it. So at the very least, the number of possible buyers is reduced.