While it can be difficult to justify the high cost of some tools, experience shows that you can save hundreds of potential hours spent troubleshooting if you have an adequate toolbox. Personally, I use a Fluke Microscanner2 for cable testing/toning (~$400), a Tempo/Blackbox 200EP inductive amp (tone probe) (~$50), and Jensen crimpers (~$40). Not cheap, but they're reliable and will last a long time.
If you're trying to convince your employer to purchase tools for you, demonstrate the potential savings in man-hours. For example, if a $400 cable tester can save an admin working at $30/hr roughly an hour of work every day, the tester has paid for itself in less than two weeks.