I see. MI cartridges are well worth experiencing. In your price range you could easily fit a Nagaoka MP-500, or a Soundsmith Aida. I'd take either over a Grado.
One of my arms is a 309, and it holds a Soundsmith Sussurro. It's a lovely combination. I do have one of the more expensive Grados (Statement 3) but it struggles to keep up.