Refurb LG V30+ is 17k on Amazon. Build quality would be better.
The A3 apparently has poor screen and is ~20k. Mi didn't want it to directly compete with K20, probably.
Realme 3 Pro has great reviews. I too ordered one :)
Both Samsung series' M- & A- have reported lag in interface. Most complaints are about that issue.
Mi is ignoring calls for L1 certification, probabbly they feel those making that noise are too small compared with the total number who buy seeking only Value.