There are a couple of online retailers that specialize in it. That's what we ended up doing for my wife's engagement ring and wedding band. It noticeably sparkles in direct sun, she gets comments on it pretty often.
I found my moissanite engagement ring on Etsy for a reasonable price, maybe check there? Lots of small time jewelers list their stuff on the site for really reasonable prices.
Moissanite can become cloudy if you don't clean it often. And the extra sparkle means people may judge you for having a "fake" ring. Like a polyester suit, people who know can tell by how bright it is.
Lab gems are relatively cheap and look exactly like the "real" ones. I mean exactly the same. People would only know it's a lab diamond if you had a ring the size of Elizabeth Taylor's at Applebee's.
Moissanite is a nonporous stone, so it doesn't get cloudy. It can get dirty on the surface like a diamond, but you can just rinse it off. On the other hand, a diamond will turn cloudy if it is in a house fire, while moissanite will not.
Naturally occurring moissanite is extremely rare, while naturally occurring diamond not so much. A geologist might judge you for wearing something that isn't real moissanite but a knockoff with a lower refractive index.