The Axxess basses aren't exactly thick on the ground, but the problem is that nobody cares
, so scarcity doesn't imply value.
Don't get me wrong: they seem to've been decent entry-level basses, especially considering the EQ, & that heel joint remains ingenious. But they were superseded by the short-lived Mercury line, then the Bantams, & the Axxess were long forgotten.
Though I only wish that I could do aside-by-side, it looks like the MBs were largely an excuse to jack up the XS prices. There were pretty much the same models in each line, right down to layout, electronics, & hardware. This includes your XS4
FL, which quickly reappeared as the MB4FL.
(I've always wondered why there was never a fretless entry in the XB line.
It's a cool bass, much more a working bass than a "collectible," so value effects of passive guts & repaint are negligible. While I'd say $200 is about reasonable, there's a VERY slim chance you could get as much as $300 for it, because it does have reliability going for it, & maybe a little cachet of the era, & the fact that Washburn has made so few fretless basses in its history. It'd be a great choice for an established bassist who wants to try fretless, & the markers would be great for a new player as well.