I came into this thread expecting to see a bike like this;



Which is generally what is viewed as a BSO in the UK but instead it looks like a pretty reasonable bike. The above bike was available for a reasonable £70 each if you bought 3 at once a day or so ago. I personally don't regard any bike a BSO if it performs its function well even if heavier than the norm. I've bought cheap fully rigid mountain bikes in the past and been more than happy with them.