Parts for a basic rebuild can quite cheap but you can also spend 10's of thousands, it depends on what you want .
As a guide pistons and rings about $1300, bearings $150, oil pump $500, a full set of gaskets from Nissan $300, water pump $140, timming belt, tensioner+ iddler $200 . Depends on who you know as to how much you will pay for bore+hone + clean the block but say $250, same with the crank, say $400 ( you will need to put a coller on that) , then you have to get the cil head serviced say $450+ parts if needed ( stem seals come in the gasket set), then oil, oil filter, drive belts etc.. Thats the very minimum, i'm sure you will find something else when you strip it, like maybe engine mounts, driveshaft boots etc...