Your Aspen is 10 year old technology with no hardware upgrade path. (GNS boxes do not pertain to this discussion but fyi they are repairable and upgradeable to GTN boxes at owner's discretion.)
As for the sudden stoppage it depends on the detail level to which it was addressed and what was done and not done. SB533C spells it out. But Lycoming also gives a lot lattitude and leaves it to mechanic's discretion. Was it a bare minimum just to get it legal or was it done in detail as per the SB? Was the crankshaft replaced? Did the crank, connecting rods, case, gears, etc undergo NDI? All this detail is important to me. As far as what's a safe range of hours that is subjective. Depends on your comfort level. To me there is no safe range unless parts were replaced. The safety of my pax and my piece of mind is my top priority. There have been catastrophic crank failures from prop strikes that happened many hundreds of hours and many years prior. Show me the details and we'll talk about price later...if we get that far.
As far as helping buyers, listing a plane at the very top of the price range and not disclosing the very recent sudden stoppage DH does not impress.