Review (3/5): 50/50 Chance you get a good bottle
Doesn't matter where you buy them, who you buy from, etc. There is a 50% chance you get a good bottle of polish and a 50% chance you get a bad one. I have 3 bottles from 3 different places, 3 different colors (blue white and black) and the blue one is good, the white one is meh, and the black one is completely useless. The white and black have bent brushes, and the white polish is a bit dried out but not the worst, kind of reminds me of using white-out before they changed the formula and it got all watery and they changed to a sponge applicator from a brush. The black one is awful - it's literally just clumps of dried out polish with some occasional damp spots. The blue one is okay, the polish is alright, but I wouldn't recommend using the brushes that came with these but buying a separate skinny brush for line work or whatever it is you want to do.
I should mention I have been using them to fix an enameled piece of jewelry as opposed to doing nails, as that's what the jeweler recommended (nobody local repairs enamel resin and buying enamel is very expensive and you end up with a ton leftover), so a jeweler I trust recommended nail polish with a good resin sealant and that's what I've been doing. Initially I had used an X-Acto knife to cut painter's tape around the shapes of different colors and metal but switched to this pink-colored liquid latex paint I saw on a youtube video for nail designs and it's much easier.