Back in the day I got a couple red dots for $30. They were both BSA brand, and they were both pretty junky. The one I still use today as a sight on a single shot rimfire I use for kids- learning to put a dot on the target is easier than lining up sights, so it's a good gun to use on the first trip to the range, but it burns through batteries. I have to keep a spare battery with it because it seems like I need to replace it every time I use it. The other one was pretty much unusable out of the box. On the couple guns I tried it on there wasn't enough adjustment to get it zeroed, you had to take it off the gun to change the battery, and the reticule was fuzzy. Oh, and whatever they used for paint got sticky after a couple years. I think at this point I actually discarded it. At least I got it on sale.
But through those I learned that many "bargain" red dot sights are junk. Just this weekend I witnessed a NC Star red dot have problems and it was pretty new. I figured somewhere out there there had to be a hundred dollar red dot that was good enough for use on a 22 rifle or pistol, but there seemed to be few options between the garbage that sells for $30-$80 and the well-known quality options like Aimpoints and Eotechs. I'm hard pressed to spend $400 on a sight for a $200 gun myself.
Last fall I shot a friend's Ruger 22 pistol that had a red dot sight I hadn't seen before, the Bushnell TRS-25. It was pretty basic, just a short fat tube with a button on top. You can set the power from 0-11 (like the guitar amps of yore, I guess). It seemed to work well and the owner said it was problem free. So the next time I found one on sale ($80 and free shipping, score!), I picked it up and have tried it on a couple guns. So far my opinion is middle of the road, but usable enough.
First, the good. It doesn't eat batteries like the similar looking BSA red dot I have. In fact, I went shooting on Friday and had it turned up all the way to 11 since it was very bright out. Of course, I forgot to turn it off and didn't discover it until Monday night and it was still going strong. Not too shabby.
As well, the adjustments are clearly marked and move the dot in a graduated fashion. On some of the cheap scopes a click moves the reticule some random distance, but on the TRS-25 the clicks are graduated evenly. The covers are waterproof and thread on easily.
Of course, if the review stopped there I'd be happy. But, there are some issues. The power setting button (0-11) is pretty mushy and not easy to turn on and off with gloves on. But that's acceptable to me to save some money. What is less so is that the brightest setting isn't bright enough for shooting at high noon in the summer. It's very hard to pick up the dot unless it's against a black background. As well, I've found it rather time consuming to find the dot at all many times. With an Eotech or an Aimpoint that certainly isn't the case.
But the real deal killer is that mine does not seem to be holding zero. Right now I have it mounted on a 22 pistol, and it seems every time I take it out for shooting I need to adjust it. Well, maybe not every time, but I know I've had to adjust it thrice in less than 10 shooting sessions. This isn't a gun that is knocked around in a holster, it spends it's life in a padded case when it's not being used. And if it's off by 3" at 10 yards a third of the time, that's not super useful. I'm hoping it needs to take a set or wear in or something and it'll stabilize.
But there aren't a lot of other affordable options out there. The Burris Fastfire is now made in China, and I've heard serious quality issues with recent models. That's unacceptable in a sight that costs $200. I'm tempted by the Vortex red dots, but I've heard they can be hit or miss on quality as well. For now I'll keep using this one on my 22 pistol until something else comes along that seems to offer quality at the right price point. It's a fast growing market, and manufacturers are introducing new products all the time.