Upstate,
I wish I'd found this site BEFORE I bought my '96. Mine was purchased in 2001 - right at the 5th year of service.
I got it with 68K. The first problem was the A/C, that cost me $1400 - I don't have the tools to do this... this went bad at 72K.
The second concern was the seat heater. Stopped working at 78K, caddy said they could replace the seats for $2400. No, I didn't bite... I may go after this later in the summer?
The next was the cabin fan at 88K. This happened right in the middle of summer in Yellowstone N.P. It was well over 90 degrees - this one made me mad!!! I did the work - $225 for the fan and worked through a stupid design flaw whereby one rocks the motor forward or cuts the firewall, sigh...
The next was standard maint. The water pump and hoses, gotta get a special tool, however, get used to that with this car! My cost was cheap compared to the dealer, they wanted $1200 for the whole job!!! Did this at 112K.
Plugs and wires - $150 or so... did this at 112K, as well.
The rear brakes, cheap... but, you need to rent a special tool, sigh...
The other stuff, like the dash - look closely at the sealed area around the top of the unit, you can tell if it has been messed with. They either work, or they don't. Mine was fine, but a lot of people told me they had issues with this.
The big issue is the head gasket - you buy that problem and it'll cost you BIG, $4500 Big!!! This is a crap shoot... the person trading that car MIGHT have taken care of it!!!??? BUYER BEWARE!!!
All in all, I'd do it much differently in 20/20 hindsight. I'd have bought at 20K and turned it right before 50K. Buy at two years and trade before five. If I add all of what I've done plus the $14600 I paid for the car I could've bought newer, traded in, and start all over again with far less problems.
So, '97 through '99 is getting a bit old. I'd try for an '03 with 20K, or so, and trade it before you have to buy tires.
My experience and 2 cents worth... your mileage may vary!
Good luck!