ironically… it’s been mostly my DVD-As that having been going up in value since the format is dead and they are going OOP.

Steely Dan Gaucho on SACD? – bought 3 copies for $15 each and still worth $15 each
Steely Dan Gaucho on DVD-A? – bought 3 copies for $15 each and now worth $90 each

Of course, some SACD titles with stunning 5.1 surround mixes that went OOP are soaring in collectable value, such as Roxy Music Avalon and Bryan Ferry Boys and Girls, buy these are the exception rather than the rule with SACDs (thankfully!  even though i have collectable copies that i will sell later).  these have increased in value mainly because the only surround mix known to man is on them (in DSD quality) and only a limited number sold before they went OOP.