I got on my Clash of Clans today, and much to my dismay, I had been raided. When I went to rearm my traps, I realized it would cost me 36,500 gold. That may not be a lot to some people, but for just traps, that seems to me like a waste of money. Are traps really as practical as they seem for the costs to re-arm them?
It depends on your play-style really.
Some people like to only use a special few and ignore the really expensive traps because they don't get much out of it for the amount of gold they spent, and instead just buy a special few that might make a slight difference.
Others go about buying every trap they can afford.
IMO, it's not worth it going on the second option. It costs to much for what your actually getting in defense.
Traps are pretty essential to maintaining a solid defense for your base.
The more powerful traps cost more to re-arm, but are generally more useful for base defense than the cheaper ones. In particular, the seeking air mine and the giant bomb are both traps that are reasonably expensive but have specific defensive purposes.
There's no requirement that you re-arm all your traps every time they are triggered. If you don't have that much gold to protect, chances are it's going to be a waste of money to set them. On the other hand, as your town hall level goes up, the percentage of your overall raid/collector gold you need to invest in order to reset them goes down significantly. At TH7 and TH8, I never had any problem with the cost of resetting traps.
A better idea is to use some strategy in trap placement - put the traps in spots where they won't be triggered by weak raids (ie, people going for your collectors, or an exposed town hall). Instead, use them to protect high-value targets near the center of your base.
Traps placed further in your base get triggered less often and tend to be more effective. They can't be baited as easily, and raiders have less control over their units later during a raid. Thus, your return on investment for arming them is much better.