About 4 years ago, I bought my 2004 L35 in similar condition. It had about 2100 hours on it and everything worked.
Since then, I've replaced: seat, almost every hydraulic hose (~30), several cylinder seals, fuel lift pump, fan belt, battery cables and battery. Some of the pins and bushings, especially the backhoe swing, need repair, but it's serviceable.
Having the hoe available has sure been convenient. The other day I encountered a hidden stump right where I needed a swale. Turned around, and 10 minutes later the stump was out of the way.
I'd say $9-10k and, if you have the time and ability to make repairs yourself, go for it. If you'd have to take it in for repairs, it would get expensive.