jerryc41 wrote:
Metz is a good brand, but I myself wouldn't buy a used flash. To me, it's like buying a used light bulb. That doesn't make much sense, I know, but I'd prefer a new flash.
Yongnuo (China) and Nissin (Japan) are two brands worth considering. Getting one that works TTL would be a good move.
You said flash is like light bulb but I found that flashes don't wear out with use as much as cameras.