I'm wondering will the SC230 still do me good for at least 5 years or so or will it outdated and not useful before too long?
There is no way to tell. This radio has most of the major features of all the new radios, but it does not do Trunking or digital. (It is actually the same as the BC246T without trunking). Currently,
Fresno County does not have either. It usually takes several years for systems to change to these more sophisticated systems, so you are probably good for at least 3 years, UNLESS you plan to travel to other areas where there are trunking. My usual advice is to get what you need now, because scanners will greatly improve in the next 3-5 years. If you need trunking or digital in the future, the price will be about the same but they will be better.
As for you question about $180, I pointed out where you can get a like-new for $149. This is a good deal because someone has already found a defect, and it has been repaired. If you bought it new, you might be the one finding the defect and having to return it.