Save the fertilizer and water. Unless you live in a desert or an area of extended drought, don't worry about watering your lawn. Where I live in eastern Oklahoma, we get enough rain to keep the grass nice and green. If you do think you need to water, do so at night so the water will soak into the ground instead of evaporating into the air. A little on a regular basis is better than a good soaking once a blue moon.
Fertilizer is a double-edged sword.
If you use it, you'll mow a lot more. If you don't, your grass may be too thin. However, follow my tips for mulching and mowing, and you will probably not have to use too much if any fertilizer. Do the work yourself. While this option does not save you time, it saves you money.