Unless you have enough experience to check out the equipment yourself (or have a friend who can), I would recommend buying new. You can get a fairly decent exposure unit for a few hundred bucks. Then, after getting experience, you can upgrade. You can also build your own if you're handy. There's lots of DIY stuff here on the forums. For screens, buy cheaper aluminum frames in a couple of mesh sizes on sale and a dip tank for reclaiming and emulsion. A cheap Epson 1430 printer works great on waterproof film to print positives. Good Luck!