when my wife and i started riding again, i decided to just buy a couple of cheap bikes - one from walmart and another from canadian tire. both bikes all in were under $300. they were heavy and generally not well set up, so i spent a few hours just getting them properly adjusted.
all was well and good on the flats we were doing short trips.

then one day i went down a hill. the cheap bike from canadian tire - no matter how hard i squeezed the brakes, i could not stop. i saw the metal brake calipers twist as i pressed harder to stop my descent. i wound up bailing into a bush - there was a major intersection ahead and it didn't look like traffic was about to stop if i went through it (i guess traffic would stop after i bounce off the first vehicle). i haven't ridden that bike since.

they were also simple cheap 6 speeds, and again on flat ground were basically okay. hated any hill climb, always wound up walking the bikes up.
never again. i would rather ride an old good quality bike than a crappy cheap new bike.