Proffesional offset mask in print office, 3600 dpi, costs in Poland about 8PLN it is about 2$ per A4.
I use PCBs with photoresist (I don't know manufacturer), simple solar lamp and with clearance of 0.1 mm I have never had problem with scratches on the board.
I have used light box with uv lamps, but I have found that method with two plexiglass or better polycarbonate plates, four tinkers clamps, and mirror allow me to made double layer PCBs without parallax error. So both layer are ideally fitted.
regards
KamW