Only a few types of outboards can be linked to software that will read "hours" and RPM time data. And of course the data on the ECM means nothing if the powerhead has been replaced.
Saying that any number of "hours" is the expected lifespan of any outboard is ludicrous. An outboard can fail with as little as 50 actual running hours, or it can run flawlessly for 5000+.
The number of hours it has on it is way less important than the TYPE of motor it is and the type of control system it has. The reputation of that control system, and how well it has been maintained are the things you should weigh. If the skeg or cav plate is beat to hell and/or there are signs of mud dauber nests and cobwebs under the cowling then you know it has been treated kinda rough and left to sit for extended periods. It may still be a fine motor....but it may be in need of a little love.
Personally (hours aside) I'd feel better buying an old carbureted Evinrude XP that has lived a rough life than I would buying a beautifully maintained Merc Optimax, ProXS, or anything Suzuki .... Just as an example. Because TO ME dependability and being easy to diagnose problems, aquire parts, and being able to find someone qualified to work on the thing is way more important than fuel economy and low emmisions.
Most of the time "LOW HOURS" means "Left to sit with old stale fuel in it, and a dead battery", and honestly that's just as bad as "High Hours".