Look up boostedgraygoosedesigns on Instagram. His latest post he does just this. I believe he makes just the wiring harness. You have to source the actual light itself
I've always gotten 20% to match factory. Price wise it's usually anywhere from 75 to 120. Obviously will go up the better tint you get. I'm in NY where it's illegal but the place I get it done takes it off for me, I get it inspected, then they put it back on for 70 bucks.