Cost... I traded a junkyard- spec turbo, IC, and BOV for it. It also comes with a shitload of parts- the guy has tons of parts and said if I ever need some, ask, and he'll send a big 'ole box of goodies down. Street value of the turbo stuff: ~$300. It's worth it; the car runs and drives with the engine in it.
Plans... Well, remember all that talk about the 1st gen CRX and then my AllTrac? Basically, that. I'll be converting to fuel injection, fabbing up my own intake and exhaust manifolds, retaining the 1237cc SOHC 8 valve engine and 4 speed manual tranny because there's no room for anything else. In fact, there's so little room, that in order to fit the turbo, I'm going to move the radiator to the back of the car. Don't ask... you'll see why when I get the engine in. There aren't really any struts/ coilover kits for the car, but MK1 GTi struts and coilover kits fit with a wee bit of welding/ grinding. It has a whack ass 4X120 bolt pattern, so I'll be converting it over to 4X100 and upgrading to 5th gen Si non- ABS discs and calipers all around, along with the 5th gen Si master cylinder. Wheels will most likely be '90-'91 CRX alloys with 195/60 Azenis or A032Rs. Anything larger than 14" is overkill on this car because it'll weigh under 1500 lbs with the cage and a full fuel cell, and you don't need any bigger wheels to clear the brakes that'll stop it like an F1 car.
As far as the engine goes... I found a company that will build a custom set of rods and pistons to whatever specs for $900, providing you send them an OEM piston and rod. I may stroke the engine with an '80- '83 Civic crank, but that's up in the air. I'll be fabricating my own cam gear. For converting it to fuel injection, I'll be using the SDS EFI system with coil packs so's I can get rid of the uberghey vacuum advance distributer. Turbo and IC are undecided, but will be on the large side to take advantage of the ~12,000 RPM fuel cutoff that the valve train will be built to handle. Yes, 12,000 RPM. Remember: This engine was designed and built back when Honda only knew how to design a motorcycle engine...
Of course, plans always change. Don't hold me to any of this, but give me about 18 months to put it all together.