Comment by selfhoster1312

For most teams selfhosting on 1U is more than enough which would cost about 1200€/year for housing + let's say 1800€/year for hardware acquisition/depreciation (probably more like 300€/year if you can work with second hand hardware) so that's about 3000€/year or 97% reduction.

Of course you may not want to manage the hardware yourself in which case you'd go for a dedicated server from a reputable provider (i.e. not microsoft/google) like OVH's RISE-XL, Hetzner's EX131, Scaleway's Core-9-L (or an equivalent solution from a smaller provider) for about 4000€/year.

Now let's say you add 8k€/year donations to your distro of choice, forge of choice, and other FLOSS projects and 8k€/year for backups. You got the whole thing running sustainably with >99.9% uptime for 20k€/year or 20% of the original bill.