My whole setup is used,
Paid 40 euro for a optiplex with 32gb ram and chucked in a 10tb HDD and a 2tb nvme Paid 55 euro for a Nuc with 24gb ram and it has a 500gb SSD and a 2tb nvme Paid 80 euro for a 730xd without disk's ram and CPUs
Paid 19 euro for two 2630Ls Paid 35 euro for 26 2'5 caddies Paid 11 euro per used 1tb micron ssds (got 24 of them ) Paid 140 euro for 256gb ram lol
I work for a crowd that only does foss or what ever we can build ourselves
PABX is done locally File servers of course, Asset management and tracking built in house Time and attendance built in house Generator management Mail server for outbound mails Projects board Several internal websites