Price paid is relative to quality; what's available; what you want; and funds available.
My recent build (replacing a Synology DS1513+) used a Supermicro M'brd with Intel Xeon E3-1241v3 LGA1150 CPU.
System has ran flawlessly from day one. Automatically downloading TV shows, etc and providing home backup for all local PCs.
Why not have a look at responses to "What Hardware are you using" forum to get a look at a good spread of system configs.