KAI,,,why would you keep so many weedeaters that don't work???
Parts! We always buy the same models of equipment. This way when one dies, we can strip it of cables, switches, screws, etc. A brand new weedeater last my company about 1-1/2 seasons. After that, they start crapping out and get retired. Shit breaks pretty quickly when it gets cycled between 20 or so random people.
Parts get expensive. Those $20 and $30 parts add up real quick. Imagine this: Let's say you had a defender with 175,000 miles. You kept having to buy starters, alternators, hoses, blah, blah, blah. Now, imagine if you had a second defender laying around in the same condition to pull parts from.
Also, they may all work one day then the next day we may have problems with 2 or 3 so they will sit there until Monday morning when we take the time to fix them.