That crate engine has a long list of not included but required parts, such as: electronics, wiring harness, pcm, oil pan that fits a gbody, drive by wire kit pedal kit, front accessories kit, custom exhaust, flex plate and adapter or 4l60, swap with a Trans controller.
Yes your right but most of it can be found reasonably priced in the salvage yard. My Olds 455 build would have been more expensive from a fuel injection standpoint and still required other high priced items like new headers, transmission upgrade, etc. In my case, doing a 455 right would have cost more and yielded less desirable results. Buying a low mileage engine complete is definitely the way to go.