Ok good info. 100 bucks doesn't give you a lot of options. Well with 5 plants, if your pressed on doing them all at once I'd go with this....
http://www.htgsupply.com/Product-400-watt-High-Pressure-Sodium-Ballast-Kit.asp ... Its a bare kit but will grow 5 nice sized plants. I've wired one before and its not hard at all, comes with the diagram. This wont leave you with any money for something to veg them under so you'd just have to use it all the way through the grow. This....
http://www.htgsupply.com/Product-HTGSupply-400-Watt-HPS-Lamp.asp ... to go in it. This puts you close to 100 bucks already. Assuming you can use some buckets or containers lying around and get cheap soil the only thing you have to worry about is heat. The air has to be exchanged in there or at least moved around in a big area to get the plants co2 to breathe. A couple of fans blowing air around may be enough. When I wired mine I made a makeshift cool tube with some ducting and a shitty thin glass vase. There are videos on youtube for cutting glass by using string lighter fluid and cold water. It works just cant have glass that's too thick. With that said if you don't need to do all 5 plants at once something like this ......
http://www.htgsupply.com/Product-HTG-Supply-2-Foot-4-Lamp-High-Output-T5.asp would work and keep heat down. I wouldn't put more than 3 plants under there, Most likely just 2. With the extra bulbs so you have 4 grows and 4 blooms would take it up to about 85 buck leaving 15 for pots and soil. As Voi said checking out Buds for less is a good idea. Heres a link....
http://www.scribd.com/doc/36777521/Marijuana-BUDS-for-Less-See-More-Buds-HQ .... In this book he uses MG soil which a lot of people says burns seedlings but it doesn't unless you over water. It is cheap and easy to use. Probably a good idea for your first grow. After that read a grow bible, ed rosenthal, greg green, and jorge cervantes all have one, pick and read at least one. So hope I helped a bit. If you have any questions Ill check back on this thread tomorrow/later.