@niodari I've been diy building/assembling desktop computers, modding mac minis for music server exclusive duty for many years. Also was in midst of researching and planning building/assembling an extremely high end bespoke streamer, which didn't pan out as I was provided with opportunity to purchase a custom build that pretty much replicated what I was intending to build. The bespoke streamer contains $4k worth of parts plus cost of subscription to Euphony OS. Add $6K for LPS to power it. I can tell you very factually vast majority of off the shelf don't come close to this. One can open up any of these streamers and determine the exact cost of these components, vast majority use parts you or I could purchase. Some use custom build motherboards, but even those aren't that expensive, I'd estimate $1k in internal parts for many. Keep in mind one isn't paying for parts alone, enclosures, R&D for seamless use and optimizing OS, and proprietary music players if offered. At the top end, add nice power supplies, proper rendering, even more R&D, there is good reason the Taiko Extreme, Wadax, Aurender, Innuos, etc. best streamers cost big bucks. One then needs to add in business model costs, distribution, dealer markups, etc.
Bottom line, each individual has to determine cost/value proposition. Many things other than cost of internal parts enters equation. DIY will require one's own R&D, many hours labor, hassles, steep learning curve, no warranties, may not be any technical help, more things I'm probably forgetting. I'd never claim off the shelf to be ripoff, diy not for faint of heart!