Do it yourself! Touch-up brushes are unusable but Holts (England), Multona (Italy) or Dupli-Color (Germany) sell the same acrylic paint in 400 ml spray cans, and those are excellent. You can find the matching paint in their catalog based on your car's paint reference number. You may have to check more than one of those, their color range is not exactly the same (for instance, I could find the exact match for my Red of the Long Valley only in Dupli-Color and the Anthracite Grey used on the upper frame of the doors only from Multona). These lacquers are enough for small scratches but to repair larger areas, especially if the plain metal can already be seen, you will need the primer of the same paint family, too. The primer is a thicker paint, acting as a filler as well; and being thicker, it is much less transparent than the lacquer, one layer of the primer covers the surface much better than two or three layers of the color lacquer. Thus, if you do use the primer to make the imperfections and color differences of the underlying surface disappear, you will be able to spare a few layers of the lacquer and to obtain a better finish.