All runners need a watch. Running watches vary greatly in price, quality, and features.
For our purposes a chronometer is the only required feature. Memory for up to 30 laps would be beneficial, but not necessary.
A cheap watch will last a season or two of running. My $35 Ironman Triathlon watch has lasted for over 5 years. Similar models have been known to last for a decade.
Watches can be found online, or at stores such as Target and Walmart.
Below are links to watches that would serve our purpose.