I have a '98 Lt. Carmine Red Metallic convertible and I LOVE it!
Issues: I bought mine in 2004 with 25,000 miles on it and it's been a great Vette. I've never had any oil consumption issues and the column lock recall was probably done long ago on the one you're looking at, as it was on mine. The dealer should be able to verify that for you.
The only issue I had with mine relates to the infamous leaking battery issue in early C5's. After I'd had it about 6 months, I got a check engine light and reduced power code one day. I killed it and after talking to my mechanic by phone, I cranked it back up and drove it to his shop.
He determined the tac module needed to be replaced and suggested I take it the dealer to let them check it, as we thought it would be covered by my warranty. The dealership came back at me with the explanation that a previous battery had leaked at sometime and a $3400 estimate claiming I needed to replace the wiring harness, and (I think) the BCM! And it would not be covered by warranty either. After they revived me, I called Kevin back and he thankfully told me to bring it back to him.
Long story short - he went through the front passenger wheel well, checked the wiring harness, replaced the tac module, cleaned and applied a baking soda wash to everything he could get to in the vacinity. Then he sealed everything possible with the liquid stuff that hardens into a plastic shell and fabricated and installed a battery box to contain any future leaks.
Parts and labor came to $427. I'm just short of 85,000 miles and it's never caused me another moment of grief.
I don't know what the one you're looking at would go for, but $23,000 for a coupe sounds high to me.
After saying all that, I'd suggest buying the latest model you can afford because every year of the C5 model run was better than the year before. But I wouldn't walk away just because it's a '97 or '98.
Good luck with your search.
Jane Ann
BTW - here's a recent photo of mine - for color comparison, of course: