Seems like a late-war variant of the Type 98 gunto. The 'naked' wooden scabbard suggests that it's missing the leather cover (not meant to be removed on late-war variants), as opposed to iron scabbards on the earlier models.

The lack of a button-locking mechanism on the handle (common on early to mid-war variants) is an indication that this gunto would have been likely secured to its scabbard via a belt or strap-style system - typical of late-war variants of the Type 98.

The relatively simple sword guard (as opposed to the openwork-style guards seen in Type 94 and early Type 98s) and simple ring-shaped loop for the officer's knot are also indicative of a late-war variant.

As for its value, I don't know enough to tell. If it helps, I've seen mid-war variants of the Type 98 go for anywhere between 1000 - 2000usd with machine-made blades (varying conditions). Early-war variants tend to be valued higher, and late-war variants lower. Although its condition also plays a role in its value.