As others have said, there is a definite difference between a "basketcase" compared to a "runout" engine.
I purchased a runout engine and prop from an RV-4. Did a MOH just to make sure everything was kosher, and ended up spending less than $16k for an IO-360 and CS prop installed! If I had to pay full shop rates for the MOH, I would have been closer to $25 - 28k for the engine/prop.
I did the same for a Continental C-85-12F that I installed on my other plane. The engine had been sitting on the floor in the back of a hangar for about 20 years before I purchased it for 30% of it's overhauled value. I did my own overhaul, and have flown for the past eight years behind a very reliable little engine! Total cost to me was about 50% of it's overhauled value.
If you're considering a basketcase, you should be paying basketcase rates! You should consider every accessory / case / crankshaft / cylinder / etc to be junk until you send it out for IRAN (inspect and repair as necessary) or overhaul.
You should also consider that there are a lot of details to an aircraft engine overhaul that are more than just turning wrenches. There are specialized tools and equipment, most parts will be shipped out to be cleaned and inspected, there are very strict tolerances for bearings, rings, and pushrods, and lots of "gotchas" that could make a simple overhaul turn into a nightmare.
Not to discourage you. I had a mentor hold my hand through both overhauls. Without a mentor, I could not have done an acceptable job!
Good luck!