It does pay to be careful when looking at inexpensive accessories. I ddon't think every low cost accessory is bad. there are some really great things you can get for your rifle that don't cost an arm or a leg. Its just that when I first got into ARs, I tried to save some money and bought from Tapco, CTD, Sportsmans Guide, etc. I learned after a short time that trying to save cost on the knock offs and just plain crap they sell is really not worth it. I easily spent $700-$800 on those things and was screwed every time with horrendously bad products. It was moeny that could have gone toward an ACOG, an Aimpoint, an EOTech, or even a new upper.
The cheap scopes look nice in the catalog. They may even look exactly like their higher priced competitors. However, the performance of those cheap scopes and any other chicom knock off item those places pass off as quality will be seriously lacking in performance. Sometimes not even in the short term, but eventually you will know the difference. Wheteher its apparent right awway, or it takes a couplke of range sessions, the quality (or lack thereof) will show itself ion a very obvious way.
Personally, I'd rather go with no optic than a bad optic. Save your $50 or however much it costs. Keep it in the bank, put it in your sock drawer, tell your wife/girlfriend/significant other/life partner to keep it somewhere safe so you don't spend it. You will do right by yourself to save the money and put it towards something of higher quality. In the long run, it will be well worth it.