Entering at the 'budget' level leaves upgradeability on the table - but usually only from the used market.
For comparison, skip back a couple of years.
If you'd built based on a comparable chip in the IvyBridge lineup (let's say an i3-3210, with a 'new' price of $117).
Fast forward to present, you could upgrade that to something like an i7-3770 (which was ~$300 new) for about $100.
I'd expect to see similar results over time.
You're not going to find a socket compatible i7 for cheap anytime soon, usually a few (3+) years have to pass by.
Realistically, depending on your needs, an AMD Ryzen3 or Ryzen5 chip might be the better chip long-term.... with only a relatively minor price increase (vs the G4560) upfront.