The machine you describe is near new with little use. Probably has some factory warranty remaining, and it's from a dealer not strictly a private sale - so some level of dealer support. It's probably worth 85% of new price I'd guess, maybe a bit more in this market. Flipside, it's no longer current model (LX is), so maybe as low as 80% of new. Much beyond that, you'd probably be better with a new machine on finance. Check price on a new one with the same options to give you a good reference point.
One thing to watch out for is that it has fluid filled wheels for ballast, and no mention of a ballast box. it's really hard on the front axle of a tractor to do a lot of FEL work with only fluid filled wheels. It stops the rear wheels coming off the ground, so it's safe, but it doesn't transfer any load at all to the rear axle - in fact, a lot of the weight of those fluid filled rears are transferred to the front.
To understand this, consider your tractor as a simple sea-saw / teeter totter. The front axle is the pivot. They're lifting a lot of weight way out in front on the FEL. The rear of the tractor is counter balancing the front. The weight from out the front is on the front axle, and a bunch of the weight from the rear of the tractor is also getting lifted by the front axle, as it counter balances.
In short, if that was the ballast method they chose, and they used it primarily as a fork lift, then they will have worked the front end of the machine pretty heavily. 75% wear on the front tires also tells you that. (Of course, they may have used rear ballast as well, and just chosen not to sell that with the machine). Have a good look at the seals and bushings on the front axle and steering to make sure there's nothing worn. Kubotas are robust, it's not all that likely to be a problem, but something to have your eyes open about.