That Z sounds great!!
The price on the SJ seems a bit off, though...
The Super P i have on order (ETA September 2020) has pretty much everything that bass has other than the birdseyes board (i have a wenge/wenge neck) and the parallel/series switches, and I'm paying around 4k EUR new (= ~4,3k USD)
His price on the SJ is pretty much on point. The SJ is +/- $270 more than the SP, his SJ has the upgraded Ash body, the 3X option, the Glockenklang pre, and the Birdseye Maple board. When you add in the paint job and the pearloid blocks, together that's almost $600. That bass was, minimum, $5,600. If he just got it, and it's still in like new condition, $5k is actually a pretty decent deal for that bass...