$130 is overkill, I was running SNEX9x back in the Athlon XP days, perfectly smoothly. Literally any CPU made in the last 8-10 years should run these emulators very well.
An i3 6100 is a solid all-around choice for a PC, but you could get away with a Skylake Pentium G4400, or possibly even an older Kabini or Atom CPU.