What is the best rate you've been able to snag for a 31+ day? I've called 20+ Marriott's in the area and am basically getting only a $10-$15 per night discount with the sales department. Should I be talking to a manager instead or is the pricing that I'm being given appropriately discounted?

I was seeing reports on FlyerTalk about being able to get a $50-60 per night rates at lower end hotels and $70-$90 per night at full service Marriott's but I'm getting quoted double that. Some of this might have to do with May through October being high occupancy times. Any recommendations?