mercury tracer engine swap

hey, i have a 97 mercury tracer 2.0L
it has 125,000 miles on it and i'd like to swap the engine and get one with low mileage.
i cant really seem to find many engines online. the ones i do find are like $2,500! and im not sure what im buying.
i want to know if its all i need. i just want to buy a complete engine for it and go to a shop that can swap them out for me.
about what kind of price range am i looking at? i dont want to buy something and realize i need more to go with it.

thanks for any help you can offer
this is something i've wanted to do for quite awhile now. im planning on putting performace parts on this car but i dont want to burn up the engine.

thanks