I added two 13 watt PC lights to my MH stand for actinics. The ballasts were 5 bucks online the bulbs were 8 and the sockets were 4. Some sacrifical extension cords for a couple of bucks.
These were easy to wire the ballast has two wires on it a blue and a black.The blue goes to one of the sides of the socket the black goes to the HOT side of your cut cord. The hot is the wire with the little ridges running down it. The other side of the socket goes to the neutral side of your power cord. I used a piece of 14 Gauge solid to push in to the socket and then wire nutted that to the extension cords neutral. The reflectors are made from aluminum sheet I got a 2x2 piece for 15.00. I have a lot left over, maybe enough for 8 more reflectors.
Cost per 13 watt fixture was about than $18.00.
