Figure a rebuild. From your post we can assume you can't (or shouldn't) rebuild it yourself. If it's JUST hard and soft seals with labor at a reputable shop it will probably put you back about $3.5k. Depending on how many miles, there might be other major parts, housings and bearings that need replacing...worst case, up to $1400 if you go new but much less with used housings. Then there are probably about $500 worth of misc. additional components....FPD, OMP lines, coil harness, plug wires, plugs, injector cleaning etc etc. that you really should consider.
How clean is the rest of the car? How many miles? BTW, "Carbon locked" engines are very rare. If it won't turn over, even using a breaker on the front hub nut, it's probably something else.
