The normal nail polishes sold at The Face Shop, Guardian, or non-branded ones, normally costs around B$4 - B$6 or may be cheaper. However, O.P.I. costs around B$10+ 20+. People like me who don't wanna spend so much on that small bottle would rather find something similar and cheaper.
All of us know that O.P.I is a good brand because of the price but some of us may not know why is it good. I seriously impress with the quality after I tried O.P.I.
Left: when I first applied. Right: 3 weeks after I applied.
The nail polish still stays after 3 weeks except for the part of my new grown nail. Normally, using the normal nail polish, it starts to get lesser and lesser after a week, because we wash our hands often, and it peels. You know what I'm talking about if you use nail polish.
O.P.I. can really extend wear. I believe it can stay for more than a month. Another good thing about it is it doesn't have awful smell.