First, if you really want lots and lots of information and opinions, consider becoming a member. Many members never even bother to look at the Guest Forum and there are thousands upon thousands of posts on the Member Side.
You can overhaul an engine to service limits (not recommended) for $30,000 or so. A good (new limits) overhaul at a good shop will run about $55,000 including re installation. A factory re manufactured engine will be about that as well. There are pros and cons of each “rebuilding” method. Those numbers are for the IO550. The IO360 is a little less.
An overhaul to service limits will add little value to the airplane. A quality overhaul or re manufactured engine will initially add a good percentage of the overhaul cost to the airplane but the added value diminishes with use.
Again, this subject is discussed ad nauseum on the Member side. Consider joining.
I was recently quoted $38k for overhaul of an IO-550N, and paid $46k for a factory reman last summer. Labor will be around $3-5k, and new engine mounts about $2k. They will typically find a few thousand worth of other things that need doing when the engine is removed.
Doing the prop and governor as well is typically another $6k or so.