Always disliked watching fellow-mechanics cutting spokes on built wheels. Cutting stainless steel spokes can be hard on cutting tools, for one reason. And, coincidentally or otherwise, those mechanics tended to be hacks in other ways (e.g., ruining customers' freewheels by neglecting to secure the freewheel removal tool in place with a Q.R. skewer).
There are people who believe otherwise, but my experience of building wheels starting in the 1960s has suggested that the same stainless steel spokes can be used on wheel after wheel after wheel without problems.
If they were my hubs (and I have a couple of pairs of tubular wheels with high-flange Campy Record hubs that I came across that had been set out for trash collection), I'd de-tension the spokes, remove them from the wheel, and measure their length. If a prospective buyer happens to need that spoke length for the new rims, shipping the hubs and spokes in the same package should cost the same or little more and would enable the buyer to save the $70 or so that new spokes would cost.