They were decent at the time.  The issue is the age and being brand discontinued for a decade.  So no, imo not a reliable car to buy for today.

The Quad 4 was one of the most idealist engines ever built. With that there was a massive campaign that had to fix a water passage sealing issue on the head. If you are looking at a QUAD 4 , make sure the engine has had that fix.

Parts are not as readily available for these vehicles as you should expect. 

     I would not pay more than $2,000 for a Saturn at this point simply because parts might be hard to come by as it has been about ten years since they stopped making them.  Also, at the very least, you'll want to do basic maintenance on it as soon as you purchase it, e.g. change the oil and oil filter, check and replace if needed the engine air filter, cabin filter, flush the radiator, check the brake system, and flush/ bleed it out when you replace the brake fluid, check/ replace the power steering fluid, check the wheel alignment, etc.

     But if you already have one, keep it!  I have one and it is such a joy to ride and to drive.  Even at 16 years old, 199,640 miles and counting, it is still going.  The thing about getting an older car is this... you will need to do maintenance on it.  For my car, I've had to replace the CV boots (they were dry rotted) and strut assembly.  It rides and handles so much better now.  I've also had to replace the radiator, the radiator hoses, the fuel pump and fuel filter, flush the brake fluid system, DRAINed and FILLed (NOT flushed) the TRANSMISSION fluid a few times in the last 16 years (it's supposed to last a "lifetime" but GM defines lifetime as 5 years which is the effective lifetime of their products), flushed radiator system a few times as well (every one or two years now), spark plugs, valve cover gasket, brakes, rotors, exhaust manifold, turn signal switch, etc.  I spent all that money to extend the life of my Saturn L300 because it was cheaper than buying a new car, the frame is solid, and it still looks younger than its years.  I mean, I keep up the wax job on it and it still looks really good sans scratches and dings here and there.  The insurance is relatively cheaper, too, than on a new vehicle.  (I haven't figured out yet though how to get the headlight assembly off the car so I can replace the parking lights.  I've followed all the directions but it's stuck!)

     Depending on the condition of your prospective Saturn, anything at or below $2,000 would be acceptable.  It all depends on its overall condition, but especially the engine and how long you plan to keep the car.