The approximate cost of a lip tattoo comes out roughly to be $400 and $800. That covers the outside of the lip area. The price also depends on the effect you want to achieve with the service, whether you just want a lip liner or a lipstick-like effect or dark lip correction, or so on.
But a point to note here is, that a lip tattoo requires several sittings for the execution of the entire process which means you will have to invest more money in the long run.