Okay, they're going to be a few dollars. I spent $10 to outfit mine, and possibly many more guns with this trick. You can spend hundreds of dollars to fit your pistol with glow in the dark sights, if they're even available for the one you own. Unless you own a Sig, Glock or Springfield, you're going to come up empty handed for the most part. Since I have a Ruger SR9c and a Bersa Thunder Ultra Compact Pro .45; these do not have night sights available as of this writing. I know someone's going to argue that the Bersa can accept Sig sights, but mine is an older model with a fixed sight in front (I checked this). Even if they did, you would have to buy the sights, the tool to get them replaced (or pay a gunsmith) and then spend time and ammo (or buy a boresight) sighting the things in. Spending money shooting is inevitable, but saving money in life is a labor well worth the energy in my book. I'm a blue collar scholar problem solver, and results on this one made the legwork worth it.
I've watched YouTube for ideas, and have seen many people touting "Glo On" from the hobby store and their girlfriends' clear nail polish over that to protect it. My only problem with that is I don't have a girlfriend and haven't in some time, say over 18 years. That's when she turned into a wife, but I digress and needless to say, has no nail polish. I know what you're thinking; buy some yourself. With all the solvents and oils used on a gun, even just wearing the thing on my hip will deteriorate this in short order. I've tried clear nail polish on many things short of my nails and to no avail, this stuff isn't durable.
I called Gander Mountain, and after hunting down the right people, found a suitable paint and a trip to a department store in the art supplies, a suitable brush. The paint is from CS coatings and it's their jig and lure paint. You'll want either glow white or glow orange and if you're painting over dark metal or plastic, their white paint. For most gun sights, they'll have white dots or in the case of my Bersa, a white goalpost. You'll also want rubbing alcohol, paint thinner, and some artists brushes (the pointier, the better). Clean the surfaces you want to paint with rubbing alcohol, than stir your paint and dip your brush (the round or liner work best) in. As long as the sights have white dots, just dip the brush in until they fill with the desired amount of paint. With my Bersa, I had to free hand over the goal post marking on the rear sight, but the picture is awesome and I can see these in low light or against a white foreground now. The glow lasts about five minutes after a good charging, but this isn't terrible compared to most other night sight options, unless you opt and can afford Tritium ones. Again, on my guns this isn't an option and I'm not trading mine for any other guns out there. The more I shoot and carry the Ruger, the more I like it. The Bersa is the same way. Maranatha!