what kind of system / how many plants are you looking to water?
I made a sweet ebb and flow set-up from home depot and lowes that was fairly inexpensive. Bought 2 19 gallon super strech tubs and cut out six holes in each.
the water pump (i got a 190gph Pondmaster one) was about $40-50 bucks and was the most expensive part. At home depot and lowes just go to the sprinkler section or ask for the drip irrigation section. I think the part you're looking for is a screw top that connects to a sprinkler tube and its only $5-6. It comes in a 6port and 9port screw top that you can adjust and connect really cheap tubing to. To actually hook it into the water pump you need a tiny fitting (5/8" wide i think, depending on your pump) that will connect straight to the pump. You then will need to superglue/caulk it to the sprinkler tube and then just buy a fairly cheap ($15-20 shut off timer) for your waterings. Its fairly inexpensive, and you only need to put in about 2-3 gallons of water at a time. Its worked really well for me.
I actually built it straight from a post that someone put up with pictures. Can't seem to find it though. I'll keep a lookout and post it if i can find it.
Good luck with you grow,