I think there comes a point where quality can get a little too low trying to chase that bottom rung. Kinda like cheap White / Bronze rated PSU's with 85c no-name caps with 1/4 of the lifespan of better made 105c Jap-cap PSU's for the sake of "saving" $20-30 (only to have to replace it in 2-3 years vs 7-10). Some sacrifices just aren't worth it, especially for anything that involves power regulation to another component (PSU / UPS / motherboard), the absolute cheapest isn't always a good idea.
For non-overclocking, B150's are the lowest I'd go personally. That last B150 -> H110 step down loses a lot, not just the chipset limitations itself but often the stuff it typically gets mated with (eg, lowest grade ALC 8xx audio chipsets that may start to "leak" / "squeal" in analogue outputs under load after a year vs shielded 1150 audio chips, or Realtek LAN chipsets that may suck up to 10% of a budget CPU vs Intel LAN that's only 1-3% under the same heavy network transfer, etc).
Same with Haswell's, H81 boards are dirt cheap but limitations like 2x USB 3.0 ports mean you either need cheap 3rd party "Asmedia" controllers to add more (which adds to the cost), or worse those 2 ports are at the back so either you're stuck with USB 2.0 only at the front, or you physically pull the PC out and turn the case around every time you want to plug a USB 3.0 device in, the "novelty" of which wears off pretty quickly vs buying a B85 board for barely $10-$20 more.