Suggestion on Fiber tester

I am in the market for a simple fiber tester. I have about 80 pairs running through my complex and we are running into some possible issues with some of the really old ones. The pen light to confirm that it's the right strand is going to require a little bit more insight to determine if there is an issue with fiber in conduit or patch. I don't need something super fancy, just need something that gives a good, bad or "holy crap is that concrete you are testing on" for starters. I am also shooting for about $150-250 tops. Any suggestions? Thanks! Blake