Yeah, they broke, are in storage, landfill (shudder), in a collection ... or ... in regular use!
And of course the good stuff is in short supply, so prices rise with demand.
A1200s are what most everyone wants for retro gaming, with the wedge case, harddisk, AGA graphics etc, yet A500s arn't worth spit here even though they're even more 'retro' ... go figure.