1) several thousand
2) Changes a lot.
Main system last week was my Zoom rig - after quickly tiring of the fisheyed output of an Apeman A77 action cam I set up a kinda sketchy video system with an Elgato Camlink 4K and my old D5100 DSLR. For sound I used a CK-12ish sort of LDC mic I built for one session and for others I played with an EV RE-10 dynamic mic, both running directly into my Acer Concept D laptop. Monitored with Sennheiser HD-25-13s (600ohms) plugged into my Neothoriator for one session and plugged into the Acer for the other sessions.
The week before I was listening to Tidal through a 2009 Mac Mini and a Bottlehead DAC. Preamp was my Neothoriator, to a custom active crossover built by PB. Jager tweeters fed by MonAmours, woofers by strapped Kaiju monoblocks.
Yesterday we were breaking, I mean, breaking in a new Stat amp, listening with some Stax 507s after I dropped and broke my Nectar Sound headphones
In our home theater we have an Epson 4010 and a 96" Silver Screen screen. Streaming from a Fire TV, Denon AVR-X3300W receiver as DAC/preamp. It's a small room - 11 x 14- so I am running 5.1. A Stereomour II feeds Jagers for the mains. Surrounds are Blumenstein Orcas driven by another Stereomour. Center channel is another Orca, driven by a strapped S.E.X. amp. Two Blumenstein Dungeness active subs for the LFE.