The Haswell Xeon CPUs are very cheap, and cheaper as the next better i7 (~50€ difference as of posting this, cheapest Xeon 1240v3 was ~250€ and the cheapest i7 4770K was ~300€). It’s kind of a “secret” tip really if you have to make compromises money-wise. It’s definitively more interesting as an i5 if you do more as just games.
With some effort (custom bios, specific boards), even a littel OC would be possible, but not as much as i5 or i7 models.