I find automatic feed systems are far more reliable than I am.
When running pump(s), light(s), etc with timers it is best to use relays to avoid timer failure. A 40 amp 12 vdc coil activated relay will run about $5 Canadian at an automotive/hardware/tool shop. I use plug in adapters to turn on the relay and I plug the adapter into the timer. Run the hot side of the light, pump, etc through the relay contacts, insulated crimp on lugs work nicely. With this setup, any cheap digital timer will work. High amperage digital timers are expensive.
I've also found that aluminum pie pans can be used for drip rings if necessary. Cut an appropriate hole in the center of the pan and cut a slot for the plant. poke the bottom of the pan with pin holes and curve the cut edges up so the pan holds the water and allows the water to go through the pin holes. Situate the pan level and put a feed hose to it.
Aquarium stores usually have nice little pumps at affordable prices.
At the start of an unknown grow, a person actually has to be there to ensure everything is going correct, but after a bit it becomes known and timers can be properly set...so the equipment can be gotten a bit at a time. Not a large rush. A small single pump grow, between $75-$100, so you you can stay late playing cards with the boys, and don't got to run home at 9:30 PM every night, people notice these little things. After a while a person realizes their freedom is well worth the hundred bucks
and before you know it, you've saved so much money from not buying weed, you got real drip rings.