If you can't budge over $100, Primary Arms sounds like the best bet and they seem to have quality customer service.
That said, if you can bump the price a little, you can get a Vortex Strikefire for $150 or a Sightron Red dot for about the same. The Vortex is China made but Vortex has some of the best factory support. The Sightron is Japan made and again, Sightron is a very customer service friendly company. I went with the Sightron as I'm a little more comfortable with the Japan manufactured optics, regardless of the company behind them, and both Sightron and Vortex have a good history.