My 1998 Kubota L2900 was a very reliable tractor, sold it a couple of years ago with several attachments and a loader for $14,500. It had about 500 hours. If the one you are looking at has a belly mower that might need service/repair. Condition is everything, I took good care of my L2900 and did a 500 hour service before I sold it.
I had a Mitsubishi D2350 - about a 1980 model. I sold it for $4000 with 2400 hours. It had a loader and was in great shape for its age. I only sold it because I was having trouble finding parts. I replaced it with a Kubota L2501. Had that Kubota L2350 been in reasonable condition and available I probably would have jumped on that instead of a new one. If it's been maintained and appears to be in good shape it's probably a good value but I wouldn't touch it personally without a loader and a three point.