OP did say "consumer Epyc", so presumably referring to the parts using the AM5 socket. From a quick check on Newegg, it looks like barebones servers for that platform start at under $1000, to which you need to add CPU, RAM, and storage. So a $3000 budget to assemble a low-end Zen4/5 EPYC server is realistic: $570 for the 16-core EPYC 4565P, a few hundred for DDR5 ECC unbuffered modules, a few hundred for an enterprise SSD, and you have a credible current-gen server from readily available parts at retail prices, without any of the enterprise pricing and procurement hassle.

That was my intention; mATX AM5 parts.

I imagine they would need quite a few servers to replace their current setup.

Then there's also the overhead of setting up and maintaining the hardware in their location. It's not just a "solve this problem for ~$2,000 and be done with it".

I don't know the actual specs or requirements. Maybe 1 build server is sufficient, but from what I know there's nearly 4,000 apps on FDroid. 1 server might be swamped handling that much overhead in a timely manner.

One server with today's tech can easily replace several servers that are 12+ years old. 4000 apps doesn't sound like a lot of work for one machine, unless you assume almost all of them are releasing new builds more than once a week. A 16-core CPU can rebuild a full Gentoo desktop OS multiple times a week.