where are you getting these prices??

you can find a b18b for around 1800-1900 and depending on how much maintainance you plan on doing while the motor is out for example water pump tensioner pully timing belt plugs and wires any seals and gaskest (prime time to do a head gasket even if it dont need it) distributor rotar and cap ect ect ect. add around 6 - 700 more

then if you install it yourself you pay 0

if someone installs it for you you should pay no more than 500 - 600 for them to do it.

so you are looking at somewhere around 2800-3000 installed by a shop or 2300-2500 if you do it your self