The test cases in Haskell are wery weak. Consider using

forAll (choose (1, length hams)) $ \x -> ...

instead of

property $ \x -> x > 5000 || x < 1 || ...

It's not about size. In point-free version cycle "10" will most likely be evaluated only once (even if you don't really need it in this case)

Thanks :)
Applicative/Monadic parsers are really great.