another way of https://github.com/scalikejdbc/scalikejdbc/pull/519 ?

build.sbt

libraryDependencies += "org.scalikejdbc" %% "scalikejdbc" % "2.4.0"

scalaVersion := "2.11.8"

Main.scala

import scalikejdbc._

object Main {
  def main(args: Array[String]): Unit = {
    implicitly[TypeBinder[Price]]
    implicitly[ParameterBinderFactory[Price]]
  }
}

Price.scala

case class Price(value: Int)

object Price extends ScalikejdbcValueCompanion[Int, Price]

ScalikejdbcValueCompanion.scala

import scalikejdbc._

abstract class ScalikejdbcValueCompanion[A, B](implicit T: TypeBinder[A], P: ParameterBinderFactory[A]) extends (A => B) {
  def unapply(value: B): Option[A] 
  final implicit val binder: TypeBinder[B] = T.map(this)
  final implicit val unbinder: ParameterBinderFactory[B] = P.xmap(this, unapply(_).get)
}