I picked up one from Harbor Frieght, years ago, because there is one down the street, it was cheap, and I needed one quickly. I had misplaced my old one. It lasted a few weeks, needed a new battery. Changed the battery, then it blinked constantly, driving me crazy, and was unreliable. So, for saving myself 50% on cost, I had a tool that I had to replace again the next month. That's not much of a savings if you have to turn around and buy a new one the next month. Maybe some things are OK to buy at HF, but sometimes saving money will cost you more in the long run. It just depends on whether it is something you can live without in the long run. But, I have to use so much geometry in what I do every day, that it was worth the price.
I also do not recommend the Harbor Frieght torque wrench. I broke my hand with it, and had to buy a new one again right away.
But, things like shop rags and pliers, I have no hesitation picking up at HF.