The ultimate AKG room mic would be a 414B XLS set on omni. (It can also be set on cardoid, wide cardoid, supercardoid, and figure 8). Yes, I think you can get a used one for $500. In fact, I think someone is selling one on this board or at Gearslutz.com for around $550. I'd buy one for that amount if I didn't already have one.