Due to the lack of recoil, you could get by with a less expensive optic on a .22 LR revolver. Magnum guns will eat cheap scopes and red dots. If you want magnification I'd stop at 2x. I won't go into all the reasons, but IMO higher magnification is more trouble than it's worth for most revolvers. Leopold makes a very nice 2x traditional handgun scope.
If I were to buy a new red dot today I think it would be one of the newer reflex type. There's all kinds of inexpensive Chinese optics on the market in the sub $100 price range. MarkAlt's Bushnell is probably Chinese. A number of guys swear by the imitation "Docter" brand reflex sights for low recoil handguns and non-waterproof applications. This is not a real Docter, as those are made in Germany and cost 400+ dollars.