Looking for Mac Pro-Specific OS Install Discs (Snow Leopard 10.6.4 - 10.6.8)

Been searching online for weeks and can’t seem to find OS Snow Leopard install discs for Mac Pro for sale anywhere (searching specifically for versions 10.6.4 - 10.6.8). iMac and MBP install discs are definitely easier to come it seems, why no Mac Pro discs out there? Looking to downgrade the current Mojave OS on my recently purchased Mac Pro to Snow Leopard 10.6.4 through 10.6.8 to run old software/hardware (audio/video editing). I have a Mid 2010 Mac Pro, 6-core (intel xenon), 3.33mgz, 96 GB RAM, Radeon 5870 GPU. Are these versions the white whale of OS discs? Are people not wanting to resell? Even bootable thumb drives with these specific install files are hard to find that are exclusively for Mid 2010 Mac Pro. Anybody got eyes on one for sale or one they are willing to sell on EBay? A link to a safe, downloadable legacy OS file would be cool too but I’ve not had much luck there either. Am I missing something here?