It's worth what someone's willing to pay for it, honestly. It is in solid shape, though. If it works well, I'll bet someone wants it.
You'll find some are worth more than others, for various reasons. Kirby and Royal, because they work almost as well as the modern ones and you can still get parts; Filter Queen for much the same reason. Stuff nobody's ever heard of isn't likely to get much, of course, unless you find the one guy that really wants it.