If you opt to purchase a cheap reflex sight (or a cheap RMR sight for that matter), then there is a high possibility of it losing its zero. This greatly reduces when you purchase high-quality scopes though. In conclusion, buying an inexpensive handgun scope (reflex sight, RMR red dot pistol sight optics, or whatever you want to call it) won’t provide good value for the money you will pay for it. Even if you can’t afford something expensive, you can still get a good red dot pistol sight scope on a good budget, as long as you know what to look out for.