It really depends on how right you want to do the swap. The biggest get started cost will be your donor car and what condition is it in. You can figure 500 or so for the donor and anywhere from 1000 to 10,000 for the other stuff. I know thats a big swing in cost but, if you start the project then decided you need to replce this and that and why don't I get into the engine while it's out, then Ya know it would really be easy for me to have the turbo redone and upgraded while its off. Now I need that Skyline intercooler. Oh yea I need some new injectors but, if I buy those I should get some big ones. Then I guess I need a new computer to control the big injectors..... As you can see it's easy to get carried away.
I would set a budget and then plan from there.