himespau 

I should use mine more frequently. I was having shifting issues, thought the derailleur just needed adjustment, didn't have the time to deal with it, so I went on a couple more rides without doing it and lived with the less than perfect shifting until I dropped the chain on a hard effort and broke my rear derailleur.

NoWhammies

Thanks for all the feedback folks. Looks like I'll be purchasing a derailleur adjustment tool. Woohoo new tools!

himespau 

If you really are looking for a rationale to splurge on tools, sometimes the problem isn't that the derailleur hanger isn't properly alligned, but that the dropouts aren't aligned, which is pushing the derailleur hanger where it shouldn't be. Sure, you could just fix the derailleur hanger, but you could also do the job the right way and first make sure your dropouts are also aligned. So feel free to tell your budget that some random dude on the internet told you that you don't just need the derailleur hanger tool, but the dropout alignment tool too.

Schlafen

I tend to replace my tools periodically, especially precision tools. So have recently sold a few of my bike tools, including bb facing tool and the dropout and derailleur alignment tools. Instead of Park Tool, I purchased them from Unior this time.
They should be delivered any day now, exciting.

veganbikes

A good quality well designed tool is never a bad investment. Only rich folks have money for cheap tools.

NoWhammies

A quick search of bike shops in my area shows the Park Dag 2.2 sold out in multiple locations. Looks like I am not the only one thinking of doing some home repairs.