I went through that process. After I stopped buy good phones subsidized by the phone company & started paying full retail phones upfront, I became less interested in having a top of the line phone. I just don't wanna fork out $900 for any phone. I bought two versions of a sub-$100 phone, they both sucked and/or were defective in some way. I bought a $240, and it was OK, but I was constantly fishing for an excuse to get rid of it. I finally came to the conclusion that I had to spend about at least $400 for a phone I'd be happy with (I wanted new + 32GB internal storage + not-crappy camera + removable battery). That strategy has worked well for me so far!
I disagree, it can be done below $400. The first two generations of the Moto G where really awesome for the price (< $200). They had vanilla Android, frequent updates, reasonably good screens and were fast. I used one for a while full time while my Moto X was being repaired. And I briefly considered switching to the G full time because it had some nice features (could be bought with dual SIM and had a bumper available that could replace the back). Unfortunately, quickly after Lenovo bought Motorola, they diversified the product line and the quick updates stopped.
Currently, Nokia (they are not really Nokia, but have ex-Nokia staff and are a Finnish company) makes really great Android phones around $200-$300. They are in the Android One program and do 2 years of feature updates and monthly security updates. So far, it seems that they are keeping up this promise. Phones like the Nokia 6.1 are fast, have a nice screen, etc. Obviously, it is not a $700 phone, but speed/quality/update-wise they are very similar to the old Nexus line.
Last week I bought a Nokia 6.1 and it is pretty fast. I have been an iPhone user since 2009 (with an Android excursion 2013-2015). But my beloved 64GB iPhone SE had water damage after a bike ride through the rain last week. And I didn't want to buy a new iPhone just ~2 months before the keynote. I'll see after the keynote whether I'll buy a/the new iPhone or whether the Nokia is good enough.
At any rate, I am very impressed what they are doing. I hope they stay on this course. I think there is a place for phones with pure Android and regular updates, but that is cheaper than the Pixel line. Basically the void that Nexus left.
I have a Moto G5+. It was under NOK 2000 in January this year, that's less than USD 250. It's great. Much better value than my sister's Huawei P9 which was much more expensive..
I also am on a non-subsidised plan and have messed around with cheap phones in the past, with similar experiences. However one thing I've found that eases a good phone's price tag is buying used, through a site like Swappa or Glyde (what I have experience with). Having a hundred plus dollar discount on something that's lightly used is quite helpful, especially considering that if I were to buy new I'd just void the warrantee with rooting anyways.
You're not wrong. I returned the two sub-$100 phones for a full refund. I had rooted the $240 phone, which broke it's ability to (easily) get system updates. I sold it on eBay for maybe half what I paid for it. So my downside wasn't as bad as it could have been. I decided I'd be content pay the price for learning how to shop for a phone I wanted. I'm also saving on every $400-not-$900 I buy in the future.
I have an LG G5. I'm very happy with it. At one year, I replaced the battery, and only because I could.
If you are in the USA, what mobile carrier/network do you have? I use AT&T, and the network has been good enough. I tried T-mobile here in San Francisco for a week, and had too many "can you hear me now?" moments, so I went back to AT&T.
