You can get a basic, no-frills red dot sight for a little over $100, but as you open your wallet wider you will find sights with better features, improved ergonomics, and increased durability. For general range use, there are lots of sights costing $200 or less that will serve you well. But if you’re going to add a sight to a gun that you plan to use and carry on a daily (or near daily) basis, it makes sense to spend more if your budget allows. There’s a sweet spot for sights costing between $300 and $400 that are feature-rich, tough, and accurate. At the top end are sights costing nearly $600.