The tranny upgrade wasn't a recall; to see if it's been done, look at the front drive pulley - if there is a small cylindrical thing with cable attached (speedo pickup) on a bracket just behind the pulley, the upgrade has been done - if not, it probably still has the original tranny.
Another thing to check is the charging system - again, this is an upgrade, not a recall, so the dealer may or may not be able to tell you if it's been done. Since the LCD display is out, about all you could do to check is to take a voltage reading at idle - with the upgrade, you' get a bit over 14 volts - the original alternator barely put out 12 volts at idle. The alternator upgrade will run about $600 parts & labor.
Keep in mind that with the age will come other things - dried, cracked rubber items (hoses, throttle body boot, etc.), throttle position sensor, etc., so you will have to expect to replace older parts as they age out. Check the tires, especially the date of manufacture - if they're more than a few years old, you'll probably want to replace them on general principles - the OEM Dunlop Elite II tires on mine were about as soft as oak, despite having a lot of tread left.
If the tranny & alternator have been upgraded, go for it, if you can get the dealer to a price you are happy with. I couldn't offer a hard & fast number for you to use, though - with the odometer out, even with all else in pristine condition I'd not want to pay anything over $4000. If the tranny is original, $3000 would be my max, and I'd start saving for & planning the upgrade.
The original C bikes have a character all their own, and I'm very happy with mine.
'99 V92C with K&N, PMRT chip, Vic stage 1 slipons, and engine by Rylan Vos!