If you are in the USA, check kbb, nada, edmunds, take an average.

I think you could probably get a turbo for about the same price as a
non-turbo in a '97 at this point... or not much more. Turbos are a
much better engine and in the USA they typically came with a much
fuller set of options.

If you mean the "headlight wiper motor" that is not unusual. They go
for about $150 new. You can replace it yourself with simple hand tools
and limited mechanical experience.

Paul,

The 4-cylinder, non-turbo S engine is also good, and may get slightly
better fuel economy than the turbo.  Both get pretty good highway
mileage, but suffer a bit in town (see fueleconomy.gov in the US).  It's
the 6-cylinder in the non-turbo SE that has a bad reputation around here.

But it sounds like you're just looking for a good car and found the
Saab, so you may not care about getting an exact feature set (which is
good: with Saab's limited production volumes, you could be looking a
long time).

There were a few upgrades in the early years of the NG900 (different
steering, bigger brakes) that you'll benefit from with a 1997 model. The
1997 is the last year of the cable clutch, and clutch cables can pop at
any time...fortunately, it's a pretty simple and straightforward repair
(maybe $100, I think).  I don't think anyone can predict cable failure
(except if it's been done recently, you're probably OK).

It's generally a good idea to pay a mechanic for a pre-purchase
inspection, regardless of the make of car (or plane).  If you're in the
US, you might look at the list of recommended mechanics over at
saabnet.com to find a knowledgeable shop in your area.